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CLEVELAND — Donald Trump paid a steep price for his brutal insults and outrageous innuendo against his Republican primary rivals Wednesday when Ted Cruz, who placed second behind Trump in the delegate count, refused to endorse the GOP nominee during his nationally televised speech to the party's convention.

The arena rained boos, chants, and jeers on Cruz, widening the Republican Party’s cracks into a chasm and completely overshadowing the rollout of Trump's running mate, Mike Pence.

Trump had chosen the experienced and reliably conservative Pence to help bring the party’s insurgent, establishment, and activist factions together. But Cruz became the story of the night before the Indiana governor even took the stage.

Related: Mike Pence Strikes Unity Notes in Acceptance Speech

During the long primary race, Trump had mocked Cruz’s wife over her looks and, late in the race, linked the senator’s father to the John F. Kennedy assassination. Cruz, in turn, described Trump as a "serial philanderer," "pathological liar," "bully," and "buffoon."

Cruz paid his old rival back again on Wednesday night, a dramatic turn that galvanized Trump’s critics on the right and enraged Trump’s supporters inside the arena.

Things started out smoothly enough. Cruz began by congratulating Trump on his victory, prompting a round of cheers, then moved on to a meditation on the recent shooting of police officers in Dallas, a survey of Cruz’s conservative philosophy, and a list of Democrats’ shortcomings.

"Citizens are furious — rightly furious — at a political establishment that cynically breaks its promises and ignores the will of the people," Cruz said. "We have to do better."

The audience watched with rapt attention as Cruz wound through his lengthy remarks. But when he reached the end – and his prescription for November — the simmering resentments between the party’s establishment, conservative, and populist wings bubbled over in a fit of rage.

"If you love our country and love your children as much as I know that you do, stand, and speak, and vote your conscience," Cruz said. "Vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution."

At "vote your conscience," the audience instantly began to boo and shout.

"Go home! Go home to Texas!" a man shouted from the stands. "Lyin’ Ted!" another yelled.

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Full Coverage of the Republican National Convention

Chants of "Trump!" and "USA!" rang out and continued through the rest of his address, drowning out Cruz’s voice. When Cruz finally walked off, the arena’s boos rose to new deafening heights – perhaps the loudest moment of the convention.

The moment was foreshadowed at a Cruz rally earlier that day, when a crowd launched into boos of their own when he referred to Trump — and continued to do so as Trump’s plane, by coincidence, passed over the event at just the same moment. At several points, audience members chanted "2020!" and it was not hard to see his convention speech that night as a possible starting point for a future run.

Newt Gingrich, who spoke a few minutes later, tried to control the damage after Cruz’s speech with an improvised display of logic.

"Ted Cruz said you can vote your conscience for anyone who will uphold the constitution," Gingrich said. “In this election, there is only one candidate who will uphold the constitution. So, to paraphrase Ted Cruz, if you want to protect the constitution of the United States, the only possible candidate this fall is the Trump/Pence Republican ticket.”

The lack of support from Trump’s old rivals, including pointed non-endorsements from Ohio Governor John Kasich and former Florida Governor Jeb Bush, had been a source of tension even before Cruz spoke.

In a striking moment early in the evening, radio host Laura Ingraham used her remarks to try to shame Republicans “with wounded feelings and bruised egos” into endorsing the party’s chosen nominee.

"You must honor your pledge to support Donald Trump," she said. "Now. Tonight."

While Cruz rebelled against her advice, other rivals took Ingraham up on it, helping the party make some halting steps towards unity in November.

Marco Rubio did so. The Florida senator, who had called Trump a “con artist” who would betray conservatives, unabashedly lent his support to the nominee in a video address to the convention.

"Unlike Hillary Clinton, Donald Trump is committed to cut taxes, curb spending and get our national debt under control," Rubio said.

Wisconsin Gov. Scott Walker tangled with Trump in less personal terms during the primaries, but nonetheless made clear that he regarded him as a unique threat to the party. He endorsed Trump only two weeks ago in a tweet that did not include the nominee’s name.

Walker hugged Trump closer in his remarks to the convention but focused more on bashing Clinton and warning of the consequences if she were to appoint a liberal replacement for the late Justice Antonin Scalia.

"Let me be clear: a vote for anyone other than Donald Trump in November is a vote for Hillary Clinton," Walker said.

As was the case the first two days, Clinton was the most reliable source of party consensus. At least a half-dozen times, the audience erupted in cheers of “Lock her up!” a phrase that’s quickly become the unofficial slogan of the convention.

But as the bitter ending to Cruz’s speech and the audience’s red-faced response demonstrated, distrust of the other side has its limits.

Clinton may galvanize voters, but she can’t heal a Republican Party traumatized by a nominating contest that exposed deep policy disagreements and elevated a nominee who shattered political norms of honesty, decency, and gravitas along the way. That challenge belongs to Trump alone and, even with his prodigious talents, it may impossible to stuff the forces he unleashed back into the bottle by November. It may not be possible, period.

Pence, for his part, did what he could to promote unity, but his speech at the end of the evening had become an afterthought.

"You have nominated a man for president who never quits, never backs down, a fighter, a winner," Pence said, accepting the nomination. "Until now he’s done it all by himself, against all odds. But this week with this united party, he’s got backup!"

The vice presidential nominee — and his convention speech — embodied the "three-legged stool" of economic, social, and security conservatism that Trump upended with his own campaign. He promised to "pray daily for a wise and discerning heart" as vice president and roused the crowd by labeling Hillary Clinton "Secretary of the Status Quo."

Reaction from delegates outside the arena was mixed. Some criticized Cruz, some expressed sympathy, while others downplayed the event's significance.

"I pledged to support the nominee and I'm heartbroken that others who pledged have not done so," Marili Cancio, an alternate delegate from Florida, told NBC News.

"I think he came as far Trump's way as he could without dishonoring his wife and father," said Sondra Ziegler, a 44-year old delegate and Cruz supporter from Lubbock, Texas.

Ziegler said she was still on the fence about voting Trump.

"I'm not there yet, but I'm hoping I can be won over," she said. "I don't think tonight helped."