Kansas GovernotJeff Colyer advance votes on Tuesday, July 31, 2018. at Hilltop Learning Center in Overland Park, Kansas. (John Sleezer/The Kansas City Star via AP) (Associated Press) 
 
 Kansas GovernotJeff Colyer advance votes on Tuesday, July 31, 2018. at Hilltop Learning Center in Overland Park, Kansas. (John Sleezer/The Kansas City Star via AP) (Associated Press) 
 
 WESTERVILLE, Ohio (AP) — President Donald Trump's preferred congressional candidate — and his chief legislative achievement — are about to be tested in battleground Ohio in the season's final high-stakes special election. 
 
 The midsummer affair comes as Trump's shadow looms over primary contests in four other states on Tuesday, none bigger than Kansas, where the Republican president roiled the governor's race Monday by opposing the sitting GOP governor on the eve of the election. 
 
 The races, like dozens before them, pit the strength of the Republican president's fiery coalition against the Democratic Party's anti-Trump resistance. The results will help determine the political landscape — and Trump's standing within his own party — just three months before the GOP defends its House and Senate majorities across the nation. 
 
 Voters in Ohio and Kansas join those across Missouri, Michigan and Washington state at the ballot box. But only Ohio will send someone to Congress after the votes are counted. 
 
 The script for Ohio's special election is perhaps familiar: An experienced Trump loyalist, two-term state Sen. Troy Balderson, is fighting off a strong challenge from a fresh-faced Democrat, 31-year-old county official Danny O'Connor, in a congressional district held by the Republican Party for more than three decades. In an early, election morning tweet, Trump said Balderson would make a "great congressman." 
 
 The winner will fill the seat previously held by Pat Tiberi, a nine-term Republican incumbent who resigned to take a job with an Ohio business group. 
 
 Trump himself campaigned at Balderson's side just 72 hours before Election Day, a weekend appearance to help energize his loyalists in a district the president carried by 11 percentage points. 
 
 But there was little evidence of enthusiasm on the eve of the election as Balderson tried to connect with voters over the phone during a brief stop at a campaign phone bank. He appeared equally uncomfortable answering questions from reporters about whether Trump's appearance might blunt the impact of the recent endorsement from a prominent Trump adversary, Republican Gov. John Kasich. 
 
 Balderson said simply that it was an honor and "incredible" to appear with and be supported by the president. He called the race "very close." 
 
 "It's going to be tough, but we feel very positive, we feel very good with the amount of volunteers that we've had here, the enthusiasm, the amount of hours that we've put in," Balderson said. 
 
 It's unclear, however, whether Trump's support helps or hurts his preferred candidate. Described by campaign operatives as a "Whole Foods" district, the largely suburban region features a far more affluent and educated voter base than the typical Trump stronghold. 
 
 Kasich, a leading voice in the GOP's shrinking anti-Trump wing, previously represented the district in Congress. 
 
 The race has centered on Trump's tax cuts at times as much as the candidates themselves. 
 
 O'Connor and his Democratic allies have railed against the tax plan, casting it as a giveaway for the rich that exacerbates federal deficits and threatens Medicare and Social Security. Balderson and his Republican allies have backed away from the tax plan in recent weeks, training their fire instead on top House Democrat Nancy Pelosi. 
 
 O'Connor has dominated Balderson on the local airwaves. His campaign spent $2.25 million on advertising compared to Balderson's $507,000, according to campaign tallies of ad spending. The Republican campaign arm and its allied super PAC was forced to pick up the slack, spending more than $4 million between them. 
 
 During a lively event in a Democrat-heavy Columbus neighborhood Monday, O'Connor urged volunteer canvassers to think about what's at stake for working people, including access to affordable health care. 
 
 "They do everything right and, right now in Washington, D.C., no one has their back," he said. "That's about to change in 28 hours, because we are sprinting. We are sprinting through the finish line for this race. We are working so hard because we are part of a movement, we are part of a grassroots movement that is going to change the way politics works." 
 
 Meanwhile, more than 700 miles to the west, Kansas Republicans were fighting among themselves in the escalating battle for governor, where Secretary of State Kris Kobach was trying to unseat Gov. Jeff Colyer. 
 
 Should the polarizing Kobach win, some Republican operatives fear he could lose the governor's seat to Democrats this fall. The race could become further disrupted if Kansas City-area businessman Greg Orman makes it onto the November ballot. He submitted petitions Monday with more than 10,000 signatures for what could become the most serious independent run for Kansas governor in decades. 
 
 Trump didn't seem worried about Kobach's prospects. 
 
 "He is a fantastic guy who loves his State and our Country - he will be a GREAT Governor and has my full & total Endorsement! Strong on Crime, Border & Military," the president tweeted on the eve of the election. "VOTE TUESDAY!" 
 
 Republicans are hoping for Democratic discord in Kansas' 3rd Congressional District, a suburban Kansas City region where several candidates are fighting for the chance to take on Republican Rep. Kevin Yoder in November. 
 
 The five-way Democratic primary features labor lawyer Brent Welder, who campaigned recently with self-described democratic socialists Vermont Sen. Bernie Sanders and ascending political star, Alexandria Ocasio-Cortez, a New York congressional candidate. 
 
 Also in the race: Native American attorney Sharice Davids and former school teacher Tom Niermann. 
 
 Voters in suburban Detroit will also weigh in on the direction of the Democratic Party. Three mainstream Democrats are viewed as leaders to vie for retiring Republican Rep. Dave Trott's seat in November. The field includes Fayrouz Saad, who would be the first Muslim woman in Congress. 
 
 And in suburban Seattle, three Democrats are vying in a jungle primary for the seat held by another retiring Republican, Rep. Dave Reichert. 
 
 Senate contests in Missouri and Michigan will come into focus as two vulnerable Senate Democrats, Missouri's Claire McCaskill and Minnesota's Debbie Stabenow, are expected to easily claim their party's nominations. 
 
 Missouri Attorney General Josh Hawley is expected to take on McCaskill. In Michigan, military veteran and business executive John James is vying for the chance to knock off Stabenow. He'd join Sen. Tim Scott as the only black Republican senators if he did. 
 
 Hours before polls opened, Trump again weighed in on Twitter, casting James as "a potential Republican star." 
 
 ___ 
 
 Peoples reported from New York. Associated Press writer John Hanna in Topeka, Kansas, contributed to this report. 
 
 ___ 
 
 This story has been corrected to reflect Hawley's title to state attorney general instead of secretary of state. ||||| President Donald Trump and Vice President Mike Pence have campaigned there in an effort to get Republicans to vote for Balderson and tamp down Democrat Danny O'Connor's momentum. The candidates will square off again in the fall, but a loss for Republicans will serve as a major psychological blow ahead of the critical midterm elections. 
 
 The implications of this race, along with critical contests in Michigan, Missouri, Kansas and Washington state, will give a temperature of voters across the country that hasn't occurred since the last major multi-state primary in June. 
 
 What we'll learn tonight 
 
 IS THIS A SIGN OF A BLUE WAVE? If O'Connor prevails, it will be a strong indicator that Democrats can win in areas that have long eluded them. With only 23 seats needed to take back the majority in the House, a win in this Columbus-area district will put that in greater reach for them (plus the number will tick down to 22). If Balderson wins the final vote, Democrats will point to the margin to show gains. Former Rep. Pat Tiberi won the district with a margin of about 37 percentage points in 2016. A loss within a close margin less than two years after a strong victory for the GOP will still be a big talking point for Democrats. 
 
 HOW STRONG IS THE TRUMP BUMP? President Donald Trump's endorsement in Republican primaries has given last-minute boosts to candidates like Katie Arrington in South Carolina. His support for John James in Michigan and President Donald Trump's endorsement in Republican primaries has given last-minute boosts to candidates like Katie Arrington in South Carolina. His support for John James in Michigan and Kris Kobach in Kansas could help bring them over the line in their primaries tonight. 
 
 But will Trump's backing be enough to take Balderson over the finish line despite Democratic enthusiasm for O'Connor? The race will say a lot about the President's impact on general election match-ups in November. 
 
 A.O.C. ALL OVER AGAIN? Alexandria Ocasio-Cortez is barnstorming for progressives across the country after her unexpected primary victory over House Democratic Caucus Chair Joe Crowley in New York. She's campaigned for James Thompson in Kansas and Abdul El-Sayed in Michigan, but can she help outsider candidates in areas that aren't liberal strongholds? 
 
 What to watch tonight 
 
 OHIO-12 SPECIAL ELECTION (polls close 7:30 p.m. ET): Like many races this year, this has come down to turning out the base. Trump stumped here on Saturday to turn out his base (he won the district with 52% in 2016). O'Connor will need Democrats to turn out in droves, combined with some flips from Independents and Republicans. A mid-August race with a potential for low turnout could be the right mix for Democrats. They are hoping to replicate Conor Lamb's impressive victory in Pennsylvania earlier this year, rather than Hiral Tipernini's close but ultimate loss in Arizona. Like the Arizona special election, both candidates will face off again in November. 
 
 KANSAS (all polls closed by 9 p.m. ET): Kris Kobach, the conservative secretary of state who served on the President's voter integrity commission, has been tight in the polls in the Kris Kobach, the conservative secretary of state who served on the President's voter integrity commission, has been tight in the polls in the race for governor , but Trump's last-minute support of him on Monday could shake up the race. GOP Gov. Jeff Colyer is competing for a full term after the appointment of unpopular Gov. Sam Brownback to the State Department. Brownback's deep budget cuts to the state have been unpopular, leaving Republicans worried they may lose the seat in November. Kobach's staunch conservative views may not play as well in the general election as they might normally. For Democrats, Bernie Sanders and Alexandria Ocasio-Cortez came to the ruby red state for Brent Welders, which could upend a race that Democrats think they can flip with candidate Sharice Davids. If Welders wins, Democrats worry he won't have enough broad support to beat GOP Rep. Kevin Yoder. 
 
 MICHIGAN (polls close 9 p.m. ET): The Democratic race for the open governor's seat once again pits a Sanders progressive outsider against a well-known Democratic leader. Former state Senate Majority Leader Gretchen Whitmer has tried to boost her liberal bona fides with her experience, focusing her campaign on her work to expand Medicaid in the state. She's leading in the polls, but it was the Wolverine State that gave Sanders an unexpected win during the 2016 primaries. Abdul El-Sayed, whom Sanders has campaigned hard for, is hoping to bring those voters out again. If he wins the primary and wins in November, he would be the nation's first Muslim governor. On the Republican side, John James -- an African-American Iraq War vet -- got a boost from the President that could put him over the top and shake up the Senate race against three-term Sen. Debbie Stabenow. Stabenow is expected to win in the fall, but James could prove to be a formidable foe. 
 
 MISSOURI (polls close at 8 p.m. ET): Tonight's primary will kick off one of the most strongly contested : Tonight's primary will kick off one of the most strongly contested Senate races of the year. State Attorney General Josh Hawley is widely expected to win the Republican primary, setting him up to take on two-term Sen. Claire McCaskill. McCaskill has won by facing deeply flawed candidates in her previous elections, but Republicans are hoping this time that Hawley can avoid past mistakes. In a state Trump won by almost 20 points, you can expect to see him continuing to campaign hard here for Hawley (and for more comparisons between McCaskill and Hillary Clinton). Keep a lookout in the 1st District. Democratic Rep. Lacy Clay has faced criticism from the left, and though he's expected to win the primary against nurse and activist Cori Bush, there is potential for another Crowley-type loss in the Show Me State. 
 
 WASHINGTON (polls close at 11 p.m. ET) -- Washington state could be fertile ground for Democrats to take the majority back in Congress. The retirement of GOP Rep. David Reichert in the 8th District has given them hope in the Seattle suburbs and beyond for another seat in the House. Democrats in the state openly admit that losing here to perennial Republican candidate Dino Rossi (assuming he advances as expected in the open primary) would be embarrassing for the party. The real pièce de résistance in Washington (and for Democrats overall) could come in the 5th District, where House GOP Conference Chair Cathy McMorris Rodgers will most likely face a tough fight against former WSU Chancellor Lisa Brown. Polls are tightening in the race, giving Democrats hope they can take out the number four Republican in the House.
– Voters in five states go to the polls on Tuesday, and analysts will again be looking for clues on what the results might mean for the November midterms. Some highlights: Kansas: The GOP primary for the governor's seat might be the highest-profile contest of the night because of President Trump. On Monday, Trump backed conservative Secretary of State Kris Kobach over the sitting Republican incumbent, Jeff Colyer, notes the AP. One fear for Republicans is that if Kobach wins, he'd be vulnerable to Democrats in November. Ohio: This is a special election, not a primary, to fill the seat of retired GOP Rep. Pat Tiberi. The seat has long been held by Republicans, but Democrat Danny O'Connor is in a surprisingly close race against the GOP's Troy Balderson. A GOP loss would be a "psychological blow" to the party, per CNN, but no matter what happens, the two candidates will be squaring off again in November. Trump tweeted on behalf of Balderson on Tuesday. Michigan: An open governor's seat is at stake, and if Abdul El-Sayed wins the Democratic primary and again in November, he would become the nation's first Muslim governor. Bernie Sanders is a big supporter, notes CNN. Elsewhere, Fayrouz Saad is one of the Democrats vying for the seat of retiring Rep. Dave Trott, and she has the chance to become the first Muslim woman in Congress, per the AP. Missouri: The Senate race here is getting big attention, because it's seen as one of the GOP's best chances to unseat a Democratic incumbent, in this case Claire McCaskill. State Attorney General Josh Hawley is expected to win the GOP nomination Tuesday night. Washington state: Various congressional primaries are on the ballot, and one interesting facet is that Washington uses what the AP calls a "jungle primary" system in which all candidates regardless of party are listed on the same ballot. The top two advance. One big race is for the seat of retiring GOP Rep. Dave Reichert near Seattle.