Ted Cruz Shifts Away From Pledge to Support GOP Nominee

^{*Editor's note: This story has been updated throughout.}

Ted Cruz is moving farther than ever away from his pledge to support Donald Trump if he is the Republican presidential nominee as the Texas senator combats a series of personal attacks from the billionaire and his supporters.

"I don't make a habit out of supporting people who attack my wife and attack my family, and Donald Trump is not going to be the Republican nominee," Cruz told reporters Friday afternoon, his clearest suggestion yet that he could not back the billionaire if he is the GOP's standard-bearer in the general election. 

A day earlier, Cruz declined to say that he will support whomever the GOP nominee is — something he'd been promising for months. Speaking with reporters in Dane, Wisconsin, on Thursday, the Texas senator would only say he plans to beat Trump for the nomination when pressed on whether he would back the billionaire if he is victorious. 

Cruz's statements on Trump in recent days are a far cry from the months he spent praising his opponent while other candidates tried — and largely failed — to weaken the frontrunner.

In recent days, Trump and his supporters have pushed a string of attacks on Cruz and his family, starting with a tweet Tuesday by the billionaire threatening to "spill the beans" on Cruz's wife, Heidi. The tweet was apparently in retaliation to an anti-Trump group's use of the billionaire's wife, Melania, in an ad that Cruz has since disavowed. 

On Friday, Cruz responded to the latest chapter in the increasingly vicious feud, a story in the National Enquirer that suggested Cruz has not been faithful to his wife. The Texas senator issued a statement calling the claims in the article "completely false."

"I want to be crystal clear: These attacks are garbage," Cruz wrote on Facebook. "For Donald J. Trump to enlist his friends at the National Enquirer and his political henchmen to do his bidding shows you that there is no low Donald won't go." 

Trump denied that he was behind the story, saying he "had absolutely nothing to do with it, did not know about it, and have not, as yet, read it." 

"Ted Cruz’s problem with the National Enquirer is his and his alone, and while they were right about O.J. Simpson, John Edwards, and many others, I certainly hope they are not right about Lyin’ Ted Cruz," Trump said in a statement. 

Cruz explained during a Wisconsin radio interview that aired Thursday that he waited until January to actively draw contrasts with Trump to avoid becoming "roadkill" like other rivals who took him on.