Speaking to Texas’s delegation at the convention at a Thursday breakfast, Cruz said his pledge to support the GOP’s eventual nominee was “abrogated” when the campaign between Trump and him became personal during the primaries. ADVERTISEMENT “I am not in the habit of supporting people who attack my wife and attack my father,” he said. "Neither he nor his campaign has taken back a word of what they said about my family,” Cruz added, his voice rising. He was referring to Trump floating rumors alleging his father was involved in the assassination of John F. Kennedy and retweeting a disparaging picture of Cruz's wife, Heidi. Cruz on Wednesday night declined to endorse Trump, instead telling Republicans to “vote your conscience.” His speech drew massive boos from the audience.

"This isn't just a team sport. … This is about standing for what we believe in," Cruz told the crowd Thursday morning.

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

Cruz slammed the convention’s jeering response to his speech the night before.

"What I wanted to do last night was lay out the principles I believe we should stand for as Republicans," he said.

"I have to say, it was somewhat dismaying, that apparently some of Donald's biggest partisans, right down front, when they heard that people should vote for someone you can trust to defend our freedom and defend our conscious, defend the Constitution, immediately they began booing. I got to say that's a little bit troubling."

Cruz got a standing ovation as he entered the room, but also faced jeers and shouting from his home-state delegation. Some chanted Trump’s name and yelled that Cruz should get behind the GOP’s nominee.

"The party has spoken," one guest shouted.

"Do you realize that you can unite this party like no one in this party, even more then our candidate?" another said.

"I will have to confess, what you said would be easy to do," Cruz replied. "Whether you want me to or not, I am not going to lie to you."

One Texas delegate asked Cruz whether supporters should write his name in on his general election ballot. The suggestion was met with overwhelming groans and shouts of “no," and Cruz swatted away the suggestion. "I am not encouraging anyone to write my name in, that is not something I would suggest. I am not a candidate in this race," he said. "I respect the will of the people.” Cruz said he shared his speech with the Trump campaign well before he delivered it and had warned Trump days ago that he wouldn't endorse.

"They knew exactly what I was going to say ... they believed it would help," he said.

"If they didn't, I was perfectly happy to get on a plane and go home."

—Updated at 9:32 a.m.