Ted Cruz: I'm not a 'servile puppy dog'

Crowd boos Cruz at RNC

A day after snubbing Donald Trump during his prime-time speech at the Republican National Convention, Sen. Ted Cruz defended his decision not to endorse the GOP presidential nominee.

"I am not in the habit of supporting people who attack my wife and attack my father," The Texas senator told home-state delegates at a breakfast Thursday. During a contentious primary, Trump linked Cruz's father to the assassin of President John F. Kennedy, and threatened to "spill the beans" on Cruz's wife, Heidi.

"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," Cruz said of his decision to abandon his pledge to support the eventual Republican nominee.

Cruz — a conservative firebrand who finished second to Trump during the Republican primary — was booed off the stage Wednesday night when he urged the crowd to "vote their conscience" in November.

Taking to Twitter, Trump seemed to respond to Cruz's comments Thursday morning: