WASHINGTON (AP) — The Latest on the 2016 presidential campaign, with contests in Maine and Puerto Rico on Sunday and a Democratic debate in Flint, Michigan (all times Eastern Standard Time): 
 
 9:18 a.m. 
 
 In case there was any doubt, Mitt Romney says he "can't imagine" endorsing Donald Trump as the Republican presidential nominee. 
 
 The 2012 GOP presidential candidate says Trump, "is not a Republican in any sense of the word" and has "taken this campaign into a very deep gutter." 
 
 Romney spoke to CNN's "State of the Union" in an interview broadcast Sunday. 
 
 The former Massachusetts governor's comments came after strongly criticizing Trump in a speech Thursday at the University of Utah as dangerous and phony. Trump that night had a difficult debate in which he made a crude sexual joke and was the target of multiple attacks from rivals Ted Cruz and Marco Rubio. 
 
 Romney says he's not endorsing any candidate now, but might after March 15 when voters in some candidates' delegate-rich home states go to the polls. Rubio, who is from Florida, and Ohio Gov. John Kasich have said they'll stay in the race at least through that days' votes. 
 
 ___ 
 
 9:05 a.m. 
 
 A look at the delegate race in the 2016 presidential race. 
 
 On the Democratic side, Hillary Clinton's substantial margin of victory in Louisiana withstood Bernie Sanders' wins in Kansas and Nebraska. 
 
 When you include superdelgates — party insiders who can choose any candidate — Clinton now has at least 1,121 delegates, compared with at least 481 for Sanders. It takes 2,383 delegates to win the nomination. 
 
 For Republicans, Ted Cruz is making a small dent in Donald Trump's delegate lead after Saturday's contests. 
 
 Trump has 378 delegates and Cruz has 295. Marco Rubio has 123 delegates and John Kasich has 34. It takes 1,237 delegates to win the Republican nomination for president. 
 
 Two more contests Sunday: Puerto Rico's Republican primary and Maine's Democratic caucuses. 
 
 ___ 
 
 8:35 a.m. 
 
 What are the presidential candidates up to on Sunday? 
 
 The Republicans will be watching for results from the primary in Puerto Rico. The Democrats are holding a prime-time debate in Flint, Michigan, and keeping an eye on Maine's caucuses. 
 
 On the GOP side, Ohio Gov. John Kasich is set to campaign in Columbus with former California Gov. Arnold Schwarzenegger and then hold an evening event in Toledo. Ohio votes on March 15 and it's a state that Kasich says he has to win. 
 
 Florida Sen. Marco Rubio has events in Idaho — rallies in Idaho Falls and Boise — ahead of the state's primary on Tuesday. 
 
 Look for Democrats Bernie Sanders and Hillary Clinton on television at their debate at 9 p.m. The Michigan primary is Tuesday. 
 
 ___ 
 
 8:25 a.m. 
 
 Front-runner Donald Trump is stepping up the pressure on Republican presidential rival Marco Rubio to quit the race. 
 
 Trump triumphed in Louisiana and Kentucky on Saturday and is retaining his delegate lead in the chase for the nomination. 
 
 Rubio was shut out in Saturday's contests and is setting his sights on winning his home state of Florida, which holds its primary on March 15. 
 
 The GOP campaign tally so far: 12 wins for Trump; six for Cruz and one for Rubio. 
 
 Trump is saying "Marco has to get out of the race. Has to" and that the Florida senator had "a very, very bad night." 
 
 Rubio's campaign is rejecting Trump's call and pledging to continue attacking Trump's business record and conservative credentials. 
 
 ___ 
 
 8 a.m. 
 
 A loyalty test for Democrats? 
 
 The party's latest presidential debate is Sunday night at 9 p.m. in Flint, Michigan, and it runs two hours. That's the same start time as the finale episode of public television's "Downton Abbey." 
 
 Voters have their choice of presidential candidates — and the choice of deciding which broadcast to watch live and which to record. 
 
 ___ 
 
 7:50 a.m. 
 
 The busy weekend in the 2016 presidential race continues with two more contests Sunday and a Democratic debate. 
 
 Republicans in Puerto Rico are voting in the party primary. Democrats in Maine are holding their caucuses. And Democratic candidates Hillary Clinton and Bernie Sanders are taking the debate stage on Sunday night in Flint, Michigan. 
 
 Saturday's results: Wins for Republican front-runner Donald Trump in Louisiana and Kentucky, and for rival Ted Cruz in Maine and Kansas. Marco Rubio was shut out and is pinning his hopes on winning his home state of Florida on March 15. 
 
 Sanders took Kansas and Nebraska, and Clinton prevailed in Louisiana. 
 
 There was no serious erosion in the delegate lead for either Trump or Clinton. ||||| Mitt Romney says he didn't expect Donald Trump "to do so well." | Getty Romney: Trump will probably win but ... 
 
 Donald Trump’s path to the Republican nomination looks clear, Mitt Romney said Sunday, but that won’t stop the former Massachusetts governor from trying to throw some obstacles in the billionaire’s path. 
 
 Romney returned to his anti-Trump talking points in an interview on CNN’s “State of the Union” with Gloria Borger, reiterating much of the message from his address last Thursday. The 2012 Republican presidential nominee once again called for voters to support whichever candidate has the best chance of defeating Trump in a given state, be it Gov. John Kasich in Ohio or Sen. Marco Rubio in Florida. 
 
 Story Continued Below 
 
 Even that, Romney admitted, may not be enough to stop Trump. 
 
 “I do know that when my grandkids say, ‘What did you do to stop Donald Trump?’ I wanted to be able to say something,” Romney said, adding later that “At this stage, we say all right, he could easily become the nominee, probably most likely to be the Republican nominee at this point, but I think there’s a better choice out there.” 
 
 Asked by Borger if he regretted not jumping into the presidential race given the direction has taken, Romney offered an emphatic no and recalled telephone conversations with his wife Ann Romney in which she called the 2016 campaign “so degrading, so demeaning.” Romney also refused to entertain the notion of jumping into the race at a contested Republican National Convention this summer. 
 
 Romney did say that he expects to endorse a candidate once a clear candidate emerges to oppose Trump, something the former governor said he expected to happen by the middle of March. Romney said he “can’t imagine” supporting Trump or his likely Democratic opponent Hillary Clinton. 
 
 “I didn’t expect him to do so well. But he has tapped into an anger which is very much understood,” Romney said. “What he’s done with that anger, however, is not to build it into resolve and high purpose but to take it down a very dark alley.”
– In case there was any doubt, Mitt Romney says he "can't imagine" endorsing Donald Trump as the Republican presidential nominee. The 2012 GOP presidential candidate says Trump, "is not a Republican in any sense of the word" and has "taken this campaign into a very deep gutter." Romney spoke to CNN's State of the Union in an interview broadcast Sunday, reports the AP, after strongly criticizing Trump in a speech Thursday at the University of Utah as dangerous and a phony. Trump that night had a difficult debate in which he made a crude sexual joke and was the target of multiple attacks from rivals Ted Cruz and Marco Rubio. Romney continued, per Politico: "I do know that when my grandkids say, ‘What did you do to stop Donald Trump?’ I wanted to be able to say something. At this stage, we say all right, he could easily become the nominee, probably most likely to be the Republican nominee at this point, but I think there’s a better choice out there." Romney says he's not endorsing any candidate now, but might after March 15 when voters in some candidates' delegate-rich home states go to the polls. Rubio, who is from Florida, and Ohio Gov. John Kasich have said they'll stay in the race at least through that days' votes.