Sen. Ted Cruz, R-Texas, said Thursday morning that he is refusing to be a "servile puppy dog" by endorsing Donald Trump after Trump attacked his family during the primaries.

"I am not in the habit of supporting people who attack my wife and attack my father," he said, just hours after his controversial convention speech Wednesday night. He said Trump's attacks against his family invalidate his pledge to vote for the GOP nominee.

"And 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 maligning my father,'" he said.

His remarks came just hours after his dramatic RNC speech, in which he asked voters to "vote your conscience." The boos started in the audience then, and his last few minutes on stage were drowned out in boos from an audience that demanded he endorse Trump.

“I can tell you I’m not voting for Hillary.” -@tedcruz refuses to say he’ll vote for #DonaldTrump pic.twitter.com/2T3GJYtisP — Fox News (@FoxNews) July 21, 2016



He did say, however, that he will not be voting for Hillary Clinton.

"The standard that I intend to apply, is which candidate I trust to defend our freedom and defend our Constitution," he told an audience in Cleveland. "I can tell you, I'm not voting for Hillary."