Gov. Scott Walker will become the final top-tier candidate to join the GOP battle for the White House when he announces his bid from Wisconsin on Monday. 
 
 Walker enters the race as the favorite to win Iowa’s caucuses and with high polling numbers and plenty of grassroots enthusiasm. 
 
 He is a natural fit for the Iowa contest as a social and fiscal conservative from an adjacent state. And his appeal came into sharp focus when he captivated an Iowa audience in January with the tale of his battle against Wisconsin’s labor unions. 
 
 But there are plenty of doubts, too, when it comes to whether Walker can be the GOP nominee. 
 
 He faces a charisma question and is seen by some critics as a vanilla candidate from the Midwest who lacks the “wow” factor — the same liability that capsized the GOP candidacy of former Minnesota Gov. Tim Pawlenty in 2012. 
 
 While competing with more exuberant rivals such as Sen. Marco Rubio (R-Fla.) and Donald Trump, Walker must show he can appeal to wide swathes of voters. 
 
 He also must show he is ready for prime-time after stumbling earlier this year in national interviews over foreign policy, at one point comparing his battles with Wisconsin’s unions to how he’d take on Islamic terrorists. 
 
 “This is the major leagues and the intensity is only going to get ramped up everyday,” says GOP strategist Matt Mackowiak. “He has to prove he can perform at a high level over the long haul.” 
 
 A win in Iowa is the first crucial test, but it won’t guarantee his nomination. The last two winners of the Iowa GOP caucuses — former Arkansas Gov. Mike Huckabee in 2008 and former Sen. Rick Santorum (Pa.) in 2012 — have faded in the primary contests that followed. 
 
 “He’s clearly the frontrunner and there’s a lot of interest in him here,” said Craig Robinson, the former political director for the Iowa Republican Party. “But he still has a lot of work to do.” 
 
 Following his presidential announcement at the Waukesha County Expo Center, Walker will spend one day each in Nevada, South Carolina and New Hampshire, before beginning an all-out blitz in Iowa that includes 11 stops over three days. 
 
 He’ll be traveling the state in a Winnebago – the motor-homes manufacturer is based in Iowa – and he’s charted a course that will eventually take him to all 99 of the state’s counties. 
 
 The Washington Post reports that following Walker’s initial Iowa blitz, he’ll begin campaigning in states with primaries and caucuses in early March, including Georgia, Tennessee, Illinois, Missouri and North Carolina. 
 
 Walker trails Florida Gov. Jeb Bush in polls in New Hampshire, and Sen. Marco Rubio (R-Fla.) — who Walker has said would be a good vice presidential candidate on his ticket — is believed to be setting up a firewall in South Carolina. 
 
 That raises the importance for Walker in winning Iowa and then bottling that momentum. 
 
 “He has to win or show well in Iowa,” said GOP strategist Ford O’Connell. “If he doesn’t, he’s in real trouble.” 
 
 
 
 Republicans laud Walker as a candidate with cross-party appeal, saying he has the potential to draw on Tea Party conservatives, social conservatives and establishment-minded Republicans. 
 
 His fight against public sector unions has been front and center in his campaign. 
 
 “It’s got to be the cornerstone of his pitch,” said O’Connell. “It’s got to be his bloody rallying cry that the liberals came after him three times with everything they had and he never wavered. “ 
 
 Still, Republicans warn Walker against leaning too heavily on that one achievement. 
 
 
 
 “It’s not enough,” said Robinson. “You can’t run solely on your biography, and so far, he’s been almost solely focused on that.” 
 
 
 
 Republicans say he will need to find traction in other aspects of his record, particularly if he’s to go head-to-head with Bush. 
 
 On the stump, where observers say Walker is getting better and better, he’s begun to broaden his argument. 
 
 At the Republican Party’s Lincoln Day Dinner in suburban Detroit in May, Walker sought to highlight reforms he’s championed as governor. 
 
 Walker said he cut taxes in Wisconsin by $2 billion, cut back on regulations, turned a $3.6 billion budget deficit into a half-billion dollar surplus, fully funded the state’s pension system and reduced unemployment from 9.2 percent to 4.6 percent, while achieving one of the highest labor participation rates in the country at 68 percent. 
 
 
 
 “We transformed everything,” Walker declared. 
 
 He has boasted about defunding Planned Parenthood in the state, signed concealed carry laws and enacted stricter voter ID laws. 
 
 He also has re-upped his fight with labor unions, signing right-to-work legislation that bans the requirement that private-sector workers pay labor dues. 
 
 Still, Walker’s record will come under fresh scrutiny. 
 
 
 
 Republicans say he’ll need to be prepared to respond to criticism that he has flip-flopped on immigration reform and ethanol subsidies, while tacking to the right on abortion and same-sex marriage in an effort to appeal to social conservatives. 
 
 Walker will also need to put forth concrete policy proposals, Republicans say, to match Rubio and other senators who are viewed as stronger on foreign policy. 
 
 “He’s going to get pushed on this in the debates, and he’ll have to be confident and clear on his positions,” said Mackowiak. 
 
 Bush and Rubio will loom over the primaries as Walker’s top competition, and his campaign appears to be readying for a protracted fight. 
 
 After Iowa, Republicans say he’ll either be a frontrunner with a huge victory under his belt or a diminished former high-flyer struggling to hold on. 
 
 
 
 “He’s starting off with a lot of chips on the table in Iowa,” said Mackowiak. 
 
 Read more from The Hill: 
 
 Walker announces: 'I'm running for president' ||||| Wisconsin Gov. Scott Walker is a potential Republican contender for president. Here's his take on border security, tax reform and same-sex marriage, in his own words. (Sarah Parnass/The Washington Post) 
 
 Wisconsin Gov. Scott Walker is a potential Republican contender for president. Here's his take on border security, tax reform and same-sex marriage, in his own words. (Sarah Parnass/The Washington Post) 
 
 As Gov. Scott Walker opens his presidential campaign Monday, he will pitch himself as a penny-pinching fiscal hawk who wants lower taxes, cuts in government spending and less government assistance. 
 
 But for months here in the state capital, Walker has pushed hard to use $250 million in taxpayer money to pay for a new professional basketball arena for the Milwaukee Bucks — confusing and angering the fiscal conservatives who usually support him. 
 
 “The stark political reality is that the proposal is a $250 million taxpayer subsidy for the Bucks and their billionaire owners in a budget rife with cuts for other programs,” Charlie Sykes, a popular and influential conservative radio show host in Milwaukee, wrote in a column that listed 10 reasons the deal “is a hot mess.” 
 
 The proposal nearly derailed passage of Walker’s two-year state budget and is just one in a series of chaotic local controversies that he has had to navigate in preparation to his White House bid. 
 
 A Twitter message posted by Walker on Monday said: “I’m in.” 
 
 1 of 26 Full Screen Autoplay Close Skip Ad × A look back at Wisconsin Gov. Scott Walker’s political career View Photos The Republican is expected to launch his official campaign for president Monday. Caption The Wisconsin governor announced Monday that he will drop out of the 2016 GOP race. Sept. 21, 2015 Wisconsin Gov. Scott Walker speaks at a news conference in Madison, where he announced that he is suspending his presidential campaign. Morry Gash/AP Buy Photo Wait 1 second to continue. 
 
 “I’m running for president because Americans deserve a leader who will fight and win for them,” said the message. 
 
 Dealing with legislation at home was supposed to be the low-drama part of Walker’s year. Instead, things here in Madison have been in turmoil for months — a complication for a governor building his presidential candidacy around his ability to get things done. Walker has spent much of the year feuding not only with Democrats — a fight he relishes — but also with fellow Republicans over proposals such as the Bucks’ arena. 
 
 GOP lawmakers who usually work with him in lock step are questioning his budget priorities. Walker’s popularity also has fallen statewide, even as he pulls to the front of the crowded GOP presidential field nationally. Democrats, meanwhile, accuse Walker of using the budget and other issues to bolster his national résumé ahead of his 2016 run. 
 
 “It was put together by the governor to help his presidential prospects with the most far-right-wing group of his party, and it reflects those values perfectly,” state Rep. Andy Jorgensen, a Democrat, said at a news conference last week. “I suspect that’s why he’s leading in Iowa. He’s at the top of the polls there . . . but in Wisconsin, meanwhile, he’s at 41 percent approval.” 
 
 Walker introduced his two-year budget — dubbed “Our Freedom and Prosperity proposal” — in a speech in early February that sounded more like an audition for president than a fiscal road map. He promised to “help restore that American Dream right here in Wisconsin” by continuing to lower property taxes, freeze college tuition, consolidate economic development operations and reduce the size of the state government. 
 
 For months, Walker confidently said he would not launch his presidential campaign until completing the budget, which he expected to do in June. Instead, lawmakers spent most of the month deadlocked. 
 
 There wasn’t enough cash to pay for everything they wanted to do, partly the result of increasing costs, $2 billion in tax breaks since Walker took office and a stalled economy. And with Walker exerting less influence, other Republicans have been jockeying for power and leverage. For a month, Republican leaders canceled all public budget meetings and instead met behind closed doors. Meanwhile, Walker loosened the timing of his presidential announcement, saying it is not unusual for the budget process to drag on for so long. 
 
 In an ad titled, "Scott Walker for America," the Republican governor from Wisconsin said he's hoping to "make our country great again." (Scott Walker) 
 
 The budget finally passed last week — saving Walker from embarrassment but giving him only a few days to review it and veto individual provisions before he signed it Sunday. 
 
 Lawmakers presented Walker with red-meat legislation that he can brag about on the GOP campaign trail: right-to-work legislation, expansion of school-voucher use, repeal of a 48-hour waiting period for those looking to purchase guns, mandatory drug testing for food-stamp recipients and a ban on all abortions after 20 weeks. 
 
 At the same time, Walker also had to retreat on a series of key issues, including abandoning plans to consolidate economic development operations and restructuring the University of Wisconsin system. 
 
 The Bucks’ arena in particular put Walker at odds with fellow Republicans and local conservative radio hosts. Last year, longtime owner and former Democratic senator Herb Kohl sold the Bucks to New York hedge fund managers Marc Lasry, a major Democratic fundraiser, and Wesley Edens. The new owners agreed to keep the team in Wisconsin — but only if they got a new arena by 2017. 
 
 Walker proposed in January that taxpayers split the cost of a new $500 million arena with the former and new owners. In the past, taxpayers helped pay for building complexes for the Milwaukee Brewers baseball team and the Green Bay Packers football team. But those teams are much more popular than the Bucks — Walker admitted that he had not been to a game in years — and Republicans questioned the major expense during a tough budget period. 
 
 As time passed, the project became less and less popular. In early June, Walker tried an alternative argument: It would be cheaper in the long run to build the arena and keep the basketball team, along with the income taxes that the state collects from players, than to lose the Bucks to another state. 
 
 “The price of doing nothing is not zero,” Walker said at a news conference, standing behind a sign reading: “Cheaper to keep them.” 
 
 The sales pitch did not work. Several Republicans, especially those from rural areas far from Milwaukee, said they couldn’t support the project. Walker then tried to gather support from urban Democrats whom he largely had ignored for the past few years. Most Democrats have declined to take a stance, instead asking why the state has money for a new arena as it is slashing funding for schools. 
 
 Finally, to get the budget through before Walker’s 2016 announcement, Republican legislative leaders decided to take the Bucks’ arena out of the budget and deal with it later. 
 
 Another major stumbling block in the budget was transportation funding. Walker had proposed using $1.3 billion in loans to pay for highway projects, which several Republicans called financially irresponsible. Some suggested increasing car registration fees to generate some cash, but Walker refused to do that. 
 
 “At some point, your credit card is maxed out, and you can’t do any more,” state Assembly Speaker Robin Vos (R) said in a TV interview in early June. “When Governor Walker proposed $1.3 billion in borrowing — I just think that is irresponsible. . . . I would prefer to pay as we go. That’s a conservative position.” 
 
 Lawmakers eventually agreed to a lower level of borrowing and to delay a number of projects. 
 
 Late on the night of July 2, on the eve of the Independence Day weekend and two days into the new fiscal year, lawmakers were able to advance the budget out of committee. But then came a new controversy — an amendment gutting the state’s open-records law that had been slipped into the budget. 
 
 The proposed change would have made Wisconsin’s law one of the most restrictive in the country, no longer allowing journalists, activists and others to request to see lawmakers’ e-mails and legislative drafting notes. Such a change, retroactive to July 1, also would have further protected Walker as he enters the presidential race and finds his record under greater scrutiny. 
 
 For days, no one would take credit for the proposal. Then on Tuesday, Senate Majority Leader Scott Fitzgerald (R) outed the governor’s office for having helped draft it. 
 
 Walker said in a radio interview Friday that although his office offered suggestions on the topic, the proposal “didn’t come from us.” 
 
 The final complication came Wednesday evening, when the state Assembly was taking up the budget, as a bomb threat cleared the state capitol for several hours. 
 
 Once the threat was cleared, lawmakers returned to their chamber to debate for several more hours, to pass the budget and then to send it to the governor. On Friday morning, Walker was asked on Sykes’s radio show to assess the budget that lawmakers rushed to get to him before his announcement. 
 
 “All in all,” he said, “it’s pretty good.”
– Make room, GOPers: Scott Walker is running for president. "I'm in. I'm running for president because Americans deserve a leader who will fight and win for them," he tweeted (this time for real) today. But for the Wisconsin governor—who dropped a "barn-burner of a speech" on February's CPAC and boasted he can take on ISIS—there are, as the Hill puts it, both "high expectations and doubts." What could boost his run: his record in Wisconsin on cutting taxes and unemployment, his strong stance against organized labor, and the potential to win Iowa's caucuses based on "high polling numbers and plenty of grassroots enthusiasm," per the Hill. He's not a shoe-in, though. "He's clearly the frontrunner and there’s a lot of interest in him here,” a former Iowa Republican Party official tells the paper. "But he still has a lot of work to do." Part of that work will involve breaking away from what the Hill calls his image "as a vanilla candidate from the Midwest who lacks the 'wow' factor" to compete with more engaging candidates. Other issues: The Hill notes that critics will go after his foreign policy weaknesses, as well as lob accusations that he's "flip-flopped" on immigration. He'll also have to defend fiscal problems back in Wisconsin, adds Washington Post, including an embarrassingly late budget and financing for a new stadium for the NBA's Milwaukee Bucks—a deal that's been called a "hot mess." Finally, Walker may need to break from what some see as a one-platform campaign focused on unions. "You can't run solely on your biography, and so far, he’s been almost solely focused on that," the ex-IRP official tells the Hill. (Then there's Walker's lack of a college degree.)