Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Donald Trump has won the Indiana Republican presidential primary, crushing the hopes of GOP foes who waged a frantic campaign to halt his march to the party's nomination.

Texas Sen. Ted Cruz, Trump's chief rival, suspended his presidential campaign hours after Trump was declared the winner, telling supporters "we left it all on the field in Indiana."

"The voters chose another path. And so with a heavy heart, but with boundless optimism for the long-term future of our nation, we are suspending our campaign," he said in remarks that neither mentioned Trump by name nor offered an endorsement for the man close to capturing the nomination.

Speaking to supporters at Trump Tower, Trump -- who once derided Cruz as "Lyin' Ted" and as recently as Tuesday morning spread unsubstantiated rumors linking Cruz's father to the Kennedy assassination -- praised Cruz as "smart" and "one hell of a competitor."

"He has got an amazing future," he said of Cruz in a speech calling for party unity.

In a tweet, Republican National Committee chairman Reince Priebus called Trump the "presumptive" Republican nominee and called for the party to unite behind him.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

.@realDonaldTrump will be presumtive @GOP nominee, we all need to unite and focus on defeating @HillaryClinton #NeverClinton — Reince Priebus (@Reince) May 4, 2016

Vermont Sen. Bernie Sanders won the Indiana contest on the Democratic side of the ballot. But frontrunner Hillary Clinton still leads Sanders by a significant number of total votes and delegates nationwide, and the results of Indiana’s primary are not expected to change her path to the Democratic nomination. Sanders has pledged to compete until the final primary contests in June.

With his Indiana victory, Trump is now on a glide path to secure the 1,237 delegates necessary to secure his party’s nomination before the convention in Cleveland this summer. He is expected to easily clear the decisive threshold that Cruz and Ohio Gov. John Kasich pledged to block from his reach.

In a memo earlier Tuesday, Kasich's campaign manager said that the Ohio governor would fight on in the 2016 race. But he lags even farther behind Cruz in the delegate count and is mathematically eliminated from capturing a majority of delegates.

Related: Cruz Calls Trump 'Serial Philanderer' and 'Pathological Liar' in Blistering Attack

Trump’s victory in Indiana was particularly stinging for Cruz, who employed a series of unorthodox campaign tactics in a last-minute effort to derail Trump’s chances in the Midwestern state.

Together, pro-Cruz and anti-Trump forces spent more than $6 million on television advertising in the Hoosier State in the effort to stall Trump's march towards the Republican nomination. Cruz and Kasich announced an alliance last month to maximize opposition to Trump in remaining primary states, a strategy which backfired badly among Republican voters skeptical of a plan that Trump branded as "collusion."

In an unusual move, Cruz announced that former HP chief Carly Fiorina would be his running mate if he captures the GOP nod — despite being mathematically eliminated from getting a majority of Republican delegates at all.

And in a fiery press conference Tuesday, a visibly upset Cruz derided Trump as “a pathological liar,” a “narcissist” and a “serial philanderer” whose electoral success to date has led the country “staring at the abyss.”

"Donald Trump laughs at the people of this state, laughs, bullies, attacks, insults," he said in remarks responding to Trump's unsubstantiated theory that Cruz's father was involved in the assassination of John F. Kennedy. "I don't believe that's America."

Trump took a less-than-conciliatory tone when he responded to Cruz's charges on Twitter Tuesday evening, calling his rival "wacko."

Wow, Lyin' Ted Cruz really went wacko today. Made all sorts of crazy charges. Can't function under pressure - not very presidential. Sad! — Donald J. Trump (@realDonaldTrump) May 3, 2016

Lyin' Ted Cruz consistently said that he will, and must, win Indiana. If he doesn't he should drop out of the race-stop wasting time & money — Donald J. Trump (@realDonaldTrump) May 3, 2016

In a statement before Cruz exited the race, Trump opposition group #NeverTrump vowed to fight on but offered few specifics on how to derail the real estate mogul's progress.

"Obviously Trump’s victory in Indiana makes the road ahead more challenging," the group wrote. "We will continue to seek opportunities to oppose his nomination and to draw a clear line between him and the values of the conservative cause."

Related: Three Possible Outcomes From Indiana's GOP Primary

On the Democratic side, Clinton has engaged less with her primary rival in recent weeks, instead choosing to focus on her likely clash with Trump in the fall.

Asked about her chances in Indiana earlier Tuesday, Clinton told NBC’s Andrea Mitchell on Tuesday that her campaign “ran hard” in Indiana but quickly added “I'm really focused on moving into the general election.”