PALM BEACH, Fla. --Donald Trump won a decisive victory in Florida's primary Tuesday night, forcing home-state Sen. Marco Rubio to abandon the race for the Republican presidential nomination. The brash billionaire also picked up North Carolina and Illinois, but faltered in Ohio.
Ohio Gov. John Kasich notched his first and only victory of the primary season by carrying his home state, but he has the fewest delegates of anyone still in the running and had virtually no electoral path to the nomination.
Trump, holding forth at his resort Mar-a-Lago in Palm Beach, Florida, urged Republicans to unify in support of him.
"Millions of people are coming in to vote. This was an example of it today," he said, citing long lines at the polls and Democrats and new voters choosing him. "We have a great opportunity."
Missouri was the fifth state to hold a primary contest Tuesday. The other contender, Texas Sen. Ted Cruz, is hoping to pick up enough delegates to force a contested national GOP convention in July.
As he suspended his campaign, Rubio tried to strike an optimistic note about his party's future, while making a not-so-subtle reference to Trump.
"Do not give in to the fear," he said. "Do not give in to the frustration."
Speaking from Cleveland, Kasich said, "I will not take the low road to the highest office of the land."
Trump's plainspoken - while controversial - appeals have resonated across the country, leaving other candidates reeling for a strategy to topple the unconventional front-runner.
"He will fix everything that is wrong with the economy and immigration," said Alex Perri, a 59-year-old retired firefighter from Margate, Florida, who was campaigning for Trump in the parking lot of an Oakland Park, Florida voting place.
Trump's promise to impose tariffs on goods from countries that don't "play fair" has been particularly resonant with voters across the industrial Midwest.
Even as Trump racks up more wins, questions have intensified about whether he is doing enough to stem violence at his raucous rallies.
Trump said Tuesday on ABC's "Good Morning America" that his record-setting crowds have had "very, very little difficultly."
The New York real estate mogul backed away from a suggestion that he might cover legal costs for a supporter who punched a protester in the face during a rally last week in North Carolina. He has blamed a larger recent clash in Chicago on Democratic protesters.
In a clear reference to Trump, House Speaker Paul Ryan, the GOP's top elected leader, declared that all candidates have an obligation to do what they can to provide an atmosphere of harmony at campaign events and not incite violence.
For some voters, Trump's tone has been a turn-off.
"We need to have a man who will speak against things that are wrong," said Cathy Lewis after she cast her vote for Kasich in their shared hometown of Westerville, Ohio.
In recent weeks, Republicans who dislike Trump have banded to wage multimillion-dollar advertising campaigns against him. One political ad highlights Trump's statements that appear to encourage violence.
Trump still leads the race for delegates, with a total of 619 including his gains in Tuesday's contests. Ted Cruz has 394 delegates, Kasich has 136 and Rubio left the race with 167.
It takes 1,237 delegates to win the Republican nomination for president.