David Jackson

USA TODAY

NEW YORK — Donald Trump easily won the Indiana primary on Tuesday, all but clinching the Republican presidential nomination and calling for party unity as rival Ted Cruz dropped out of the GOP race.

"It's been some unbelievable day and evening and year," Trump told supporters at his building in midtown Manhattan, predicting that more and more skeptical Republicans will jump aboard the "Trump train" ahead of a tough fall election against Democratic front-runner Hillary Clinton.

"We're going after Hillary Clinton," Trump said to loud cheers.

The Clinton campaign said it is ready for Trump. Campaign chairman John Podesta said that Trump "has demonstrated that he’s too divisive and lacks the temperament to lead our nation and the free world."

Cruz, who finished a distant second to Trump in Indiana, told supporters earlier in the evening that "we gave it everything we've got, but the voters chose another path."

First Take: Ted Cruz 'too strategic for his own good'

Republican Party chairman Reince Priebus, who spoke with Trump as the Indiana results rolled in, declared the New York businessman "the presumptive nominee," and said in a tweet that "we all need to unite and focus on defeating" Clinton.

Hours after Trump and Cruz accused each other of being unhinged liars, the New York businessman called Cruz "one helluva competitor" after beating him in Indiana, and he added that the Texas businessman has an "amazing future."

Trump also thanked the "incredible" people of Indiana for helping him overcome deficits in early polling and ignoring negative ads about his candidacy.

Six key moments of Ted Cruz's campaign

Cruz, who had hoped for a rally that would help him force a contested convention in July, had argued earlier in the day that Trump is an unstable person who would drag Republicans down to defeat in November.

"Donald Trump is such a narcissist that Barack Obama looks at him and says, 'Dude, what's your problem?'" Cruz told reporters in Indiana.

The Indiana primary capped a remarkably angry campaign in which Trump and Cruz accused each other of being unhinged liars — including a suggestion by Trump on Tuesday that Cruz's father was somehow linked to Lee Harvey Oswald, the assassin of President John F. Kennedy.

Trump bizarrely links Cruz’s father to JFK assassin; Cruz goes ballistic

Protesting the senior Cruz's criticism of him, Trump cited an (uncorroborated) report in The National Enquirer with a picture supposedly showing Rafael Cruz standing near Oswald. "It's horrible," Trump told Fox News.

Cruz called Trump's claims "nuts" and "kooky," telling reporters that Trump "is utterly amoral — morality does not exist for him.” He called the GOP front-runner "a pathological liar" who "doesn’t know the difference between truth and lies."

Responding to what he called Cruz's "ridiculous outburst," Trump described "Lyin' Ted" as "a desperate candidate trying to save his failing campaign." He said the Texas senator "does not have the temperament to be president of the United States."

Ohio Gov. John Kasich who pulled out of Indiana last week and vowed to take on Trump in upcoming states, indicated he would remain in the race.

In a memo sent after Trump's win, Kasich's chief strategist, John Weaver, said, "Our strategy has been and continues to be one that involves winning the nomination at an open convention."

Cruz had indicated earlier in the day he would stay in the Republican race even with an Indiana loss, and his campaign had announced appearances later this week in Nebraska and Washington. But he told backers in Indiana he would continue only "as long as there was a viable path" to the nomination.

"Tonight, I'm sorry to say it appears that path has been foreclosed," Cruz said.

Trump, meanwhile, is trying to unite Republicans behind his candidacy, even as he faces continued criticism from current and past rivals as well as a variety of "Never Trump" organizations.

Katie Packer, who chairs an anti-Trump group called the Our Principles PAC, indicated it would not give up despite the Indiana results, noting that Trump is still short of the delegate majority he needs.

"A substantial number of delegates remain up for grabs in this highly unpredictable year," she said, adding there is "more time for Trump to continue to disqualify himself in the eyes of voters — as he did yet again today spreading absurd tabloid lies about Ted Cruz's father and the JFK assassination."

Indiana marks Trump's seventh win in a row, a streak that began in his home state of New York on April 19. After winning five more northeastern states last week, Trump declared himself the "presumptive nominee."

Cruz, who last defeated Trump in Wisconsin nearly a month ago, had high hopes for Indiana, a state with many conservative voters. But his campaign struggled in recent days. Former House speaker John Boehner, one of many GOP lawmakers who dislike him, described the Texas senator as "Lucifer in the flesh," while critics in the basketball-crazy Hoosier State mocked Cruz for describing a hoop as a "ring."

Clinton looks ahead, while Sanders hopes for symbolic win in Indiana

Cruz had hoped to energize his campaign by naming businesswoman — and former Republican candidate Carly Fiorina — as his potential running mate. But the move did not appear to generate many votes in Indiana.

As the primary approached, the Kasich and Cruz campaigns made a deal, of sorts, as part of a combined stop-Trump effort. While Kasich moved out of Indiana, Cruz agreed not to campaign against Kasich in future contests in Oregon and New Mexico.

Amid Trump's rise, President Obama has stepped up his criticism of Trump, telling WMUR-TV of Manchester, N.H., that the outspoken businessman is not somebody who can be considered "equipped to deal with the problems of this office."

Needing 1,237 delegates to secure the nomination at the July convention in Cleveland, Trump will now have more than 1,000 — nearly 500 more than Cruz and almost 900 ahead of Kasich.

During his campaign in Indiana, Trump said neither of his opponents had a path to the nomination.

"They're never going to get there," Trump told backers in Carmel. "We are way over and way ahead of projection and we'll do it on the first ballot. But if we win Indiana, it's over."