WASHINGTON >> An emboldened Donald Trump offered himself Wednesday as the inevitable Republican presidential nominee and called on balky GOP leaders to embrace the voters' "tremendous fervor" for his candidacy. But the billionaire businessman's latest wins didn't stop anti-Trump Republicans from seeking scenarios to deny him the GOP nomination.
Trump, who padded his delegate lead in the latest round of voting, predicted he'd amass enough support to snag the nomination outright before the Republican convention — without much difficulty. And he served notice that if GOP leaders try to deny him the nomination at a contested convention when he is leading the delegate count, "You'd have riots."
With his latest wins, Trump has won 47 percent of delegates so far. He'll need to win 54 percent of remaining delegates to clinch the nomination before the convention, according to The Associated Press delegate count.
Despite Trump's momentum, some GOP leaders and conservatives continue to explore ways to block him.
Former House Speaker John Boehner waded into the fracas on Wednesday, saying he'd support his successor, Paul Ryan, for president if Republicans can't agree on a candidate at the convention.
Boehner, who has endorsed John Kasich, said that if Republicans can't nominate Trump, Kasich or Texas Sen. Ted Cruz on the first ballot, he'd be "for none of the above. I'm for Paul Ryan to be our nominee."
Democrat Hillary Clinton, eager for a November matchup against Trump, took direct aim at him after strengthening her position against rival Bernie Sanders with another batch of primary victories.
"Our commander-in-chief has to be able to defend our country, not embarrass it," Clinton said in a speech that largely ignored Sanders. "We can't lose what made America great in the first place."
Sanders, unbowed by Clinton's commanding delegate lead, emailed supporters that his rival has hit her high-water mark and "the map now shifts dramatically in our favor." He listed Arizona, Idaho, Utah, Alaska, Hawaii, Washington state and Wisconsin as states he could win.
Trump suggested in calls to morning TV shows that the party establishment is starting to fall in line behind him. Without naming names, Trump said some of the same Republican senators who are publicly running him down have called him privately to say they want to "become involved" in his campaign eventually. He picked up an endorsement Wednesday from Florida Gov. Rick Scott.
As for his expected Democratic opponent, Trump said Clinton would be "a major embarrassment for the country" and added that she "doesn't have the strength or the stamina to be president."
Plans for a GOP debate in Salt Lake City on Monday collapsed after Trump said he'd skip the event and then Kasich's camp said they'd pull out if Trump didn't participate.
Clinton triumphed in the Florida, Illinois, Ohio and North Carolina presidential primaries, putting her in a commanding position to become the first woman in U.S. history to win a major-party nomination. Trump strengthened his hand in the Republican race with wins in Florida, North Carolina, and Illinois but fell in Ohio to that state's governor, Kasich. Votes were also being counted in Missouri, though races in both parties there were too close to call.
Kasich, celebrating his home state win over Trump, told NBC's "Today" show, "I dealt him a very, very big blow to being able to have the number of delegates."
Even before Tuesday's results, a group of conservatives was planning to meet to discuss ways to stop Trump, including a contested convention or rallying around a third-party candidate. While no such candidate has been identified, the participants in Thursday's meeting planned to discuss ballot access issues, including using an existing third party as a vehicle or securing signatures for an independent bid.
Trump said putting up a third-party candidate to block him would "guarantee" a Democratic win in November.
On Tuesday, Ryan did not rule out the idea of being drafted by the party at the convention, but on Wednesday his spokeswoman, AshLee Strong, appeared to close that door.
"The speaker is grateful for the support, but he is not interested," she said in an emailed statement. "He will not accept a nomination and believes our nominee should be someone who ran this year."
Boehner, in remarks to the Futures Industry Association first reported by Politico, said he'd back Ryan if the three remaining GOP rivals "all had a chance to win" and couldn't clinch the nomination on the first ballot.
With more than half the delegates awarded through six weeks of primary voting, Trump is the only Republican candidate with a realistic path to the 1,237 delegates needed to clinch the nomination.
Cruz is in better position than Kasich, but he also faces a daunting mathematical challenge after losing four of five contests Tuesday. The Texas senator needs to claim roughly 75 percent of the remaining delegates to earn the delegate majority, according to Associated Press delegate projections.
On the Democratic side, Clinton has at least 1,599 delegates, including the superdelegates who are free to support the candidate of their choice. Sanders has at least 844. It takes 2,383 to win the Democratic nomination.
Trump's Florida victory brought his delegate total to 661. Cruz has 406 and Kasich 142. Rubio left the race with 169.
AP writers Stephen Ohlemacher in Washington and Scott Bauer in Madison, Wisconsin contributed to this report.