CLEVELAND -- On the day he claims the presidential nomination of Abraham Lincoln's political party, Donald Trump has started things off with social-media missiles fired against the embarrassed losers still refusing to back him.

The prelude to the prime-time moment where he will accept the Republican nomination included tweeting at the people who have withheld endorsements of him -- a group that includes the two president Bushes, nominee Mitt Romney, the popular governor of the state hosting the convention, and the No. 2 finisher in the primaries.

It was the latter holdout making all the waves at the Republican convention. When Sen. Ted Cruz urged the audience to simply vote its conscience in November, the site erupted in loud boos and scattered applause.

So Trump took a shot at Cruz. He pointed out the high-stakes battle for control of the Supreme Court, which Trump said should unite the party: "Ted Cruz talks about the Constitution but doesn't say that if the Dems win the Presidency, the new JUSTICES appointed will destroy us all!"

Then he expanded the radius of those he criticized: "Other than a small group of people who have suffered massive and embarrassing losses, the party is VERY united. Great love in the arena!"

There's certainly overwhelming support for Trump at the convention. But numerous delegates also expressed lingering doubts about his conservative convictions and their distaste for his personal comportment.

It's the personal issues Cruz referred to when asked Thursday why he didn't clearly state his support for Trump in his late-evening address.

He referred to Trump attacking his relatives during the primaries: he shared a social-media post insulting Cruz's wife's looks, spread a National Enquirer article about marital infidelity, and insinuated Cruz's father may have been linked to JFK's assassination.

"If you go and slander and attack Heidi... I'm (not) going to nonetheless come like a servile puppy dog and say, 'Thank you very much for maligning my wife and maligning my father,"' he said.

He said he'd put aside his own ill will and reluctantly come to the convention and speak in support many of Trump's policies, while criticizing his opponent Hillary Clinton, despite the fact that he never got an apology for the things Trump did.

He also criticized the angry reaction from the convention floor.

"What does it say when you stand up and say, 'Vote your conscience,' and rabid supporters of our nominee begin screaming, 'What a horrible thing to say'?" If we're not voting our conscience," Cruz said, "then we are not going to win and we don't deserve to win."

Commentators suggested the ill-timed spat might damage Cruz's long-standing dream of becoming president. One called it, "The longest suicide note in American political history."

Trump supporter Ann Coulter tweeted a joke referring to the senator's Calgary birthplace. "Last night, Cruz showed that he's earned a leading role in the nation's political future. And that nation is Canada."

Five Cruz supporters interviewed at the convention said they intended to vote for Trump. Four of them said they weren't thrilled. But Jeanie Turk said she's enthusiastically made the switch.

"Anybody that has any brain power at all is gonna get behind the Trump train," said the member of the Texas delegation. She said people who had doubts about the Bushes and Romney put them aside, and now it's time to do the same for Trump.