CLEVELAND -- U.S. Sen. Ted Cruz of Texas declared Thursday that he's no "servile puppy dog" as he faced a torrent of GOP criticism over his refusal to endorse Donald Trump in his Republican National Convention speech Wednesday night.

Cruz spoke in a prime-time slot Wednesday in Cleveland and urged Republicans to "vote your conscience" in the November election.

Although he had not been expected to offer an effusive endorsement of Trump, many GOP delegates had expected to hear some expression of support for the party nominee as they struggle to unite their party to defeat the Democratic nominee this fall.

Delegates booed Cruz as he left the convention stage.

In a late-night Twitter post Wednesday, Trump called Cruz's move "no big deal!"

But on Thursday, Cruz met anger and denunciations from many sides. He was even heckled at a breakfast meeting with the Texas delegation where a vocal minority of the crowd was furious.

Cruz delivered a lengthy defense of his speech, saying the party needs to "stand for shared principles" if Republicans want to win in November.

Early in the GOP primary campaign, Cruz and others had pledged to support whomever became the eventual party nominee. But the campaigning turned ugly, and Cruz and Trump engaged in some bitter exchanges that at times got personal.

In Wednesday's speech, Cruz congratulated Trump on winning the nomination and did not mention the nominee's name again.

"Get over it, this is politics!" one man yelled Thursday at Cruz. Another told Cruz that he could unite the party by saying just a few words in support of Trump, and "you need to do it now!" A third told Cruz to "stop spinning it!"

Cruz refused and sought to portray his stance as a matter of principle.

"In that speech last night I did not say a single negative word about Donald Trump," Cruz said. "And I'll tell you this morning, and going forward, I don't intend to say negative things about Donald Trump."

He also assured attendees that he will not be voting for Democrat Hillary Clinton in the fall.

He repeated that he would listen to Trump's speech Thursday night, but he would not be endorsing the real estate mogul for president.

"I'm going to be listening to how he and the campaign conduct themselves every day from now until November," Cruz said.

During the primary campaign Trump dismissed Cruz as "Lyin' Ted," mocked Cruz's wife's looks and linked Cruz's father to the assassination of President John F. Kennedy.

"I'm not going to get into criticizing or attacking Donald Trump, but I'll give you this response: I am not in the habit of supporting people who attack my wife and attack my father," Cruz said, adding that those attacks had negated his pledge to back the eventual GOP nominee.

"That pledge was not a blanket commitment that, if you go and slander and attack Heidi, that I'm going to nonetheless come like a servile puppy dog and say, 'thank you very much for maligning my wife and my father,'" Cruz said.

Cruz said the "politically easy option" would be to back the nominee no matter who it might be, but he insisted: "This is not a game, it is not politics. Right and wrong matters."

Trump campaign chairman Paul Manafort said early Thursday that he and the campaign were disappointed with Cruz's speech.

"Cruz used very bad judgment. I think he made a mistake," Manafort said on NBC's Today show. "I think he was not respectful to the invitation by the convention to come and speak. He understood what the responsibilities are of somebody in his position, and he didn't meet them."

Asked Thursday morning about Cruz's remarks, Indiana Gov. Mike Pence -- Trump's vice presidential running mate -- said on Fox News that he was grateful that Cruz delivered a speech and that he did not hear it in its entirety.

"This was a tough and challenging primary. These were tough competitors. And I've been through a few tough elections myself, and I know that those feelings can be strong," Pence said. "There's always going to be differences and nuances in the way people express that. But what I sensed in that hall the last several days, and especially last night, is a Republican Party that is coming together around the stakes of this election."

Defenders of Cruz were few among elected officials and convention delegates.

"He's very self-absorbed, he's a narcissist and the rest of America now knows the Ted Cruz we know, and I think he's ended his political career," said U.S. Rep. Chris Collins of New York, a Trump backer.

Cruz delegate Eric Burlison, a Missouri House member from Springfield, said Cruz would have been better off sending a videotaped message as U.S. Sen. Marco Rubio of Florida did.

"People that probably four years from now or eight years from now would have looked at him as being the next guy, he lost them. They will never forget that, and they will never forgive him for that," Burlison said.

Cruz's campaign manager told reporters that some members of the Texas delegation, led by Lt. Gov. Dan Patrick, spoke to Cruz on Wednesday to urge the senator to publicly back Trump.

"He went back on his word to support the nominee. ... Your word, in politics, has to be your bond. He's politically dead," said B.J. Van Gundy, a longtime GOP activist in Georgia.

Information for this article was contributed by Erica Werner, Thomas Beaumont and David A. Lieb of The Associated Press; and by Karen Tumulty, Sean Sullivan and Jose A. DelReal of The Washington Post.

A Section on 07/22/2016