'This man is a pathological liar': Ted Cruz explodes at Donald Trump after Trump goes after his father

Sen. Ted Cruz unleashed a fierce tirade against Donald Trump on Tuesday, using his harshest rhetoric yet against the frontrunner as Indiana headed to the polls for what could be a do-or-die primary.

"This man is a pathological liar. He doesn't know the difference between truth and lies," Cruz said at a press conference. "He lies, practically every word that comes out of his mouth."

At various points, he called Trump a "narcissist and "serial philanderer," and said "morality doesn't exist" for him.

Cruz also responded at length to the Republican presidential frontrunner's suggestion earlier in the day that Cruz's father, Rafael Cruz, was somehow linked to Lee Harvey Oswald, the assassin of President John F. Kennedy.

"This is nuts," Cruz said.

The Texas senator mocked Trump's suggestions, going on a sarcastic riff to lump in Trump with famous conspiracy theorists.

"Yes, my dad killed JFK, he's secretly Elvis, and Jimmy Hoffa is buried in his backyard," Cruz said.

Trump's assertion came during a Fox News interview on Tuesday, when Trump cited a dubious National Enquirer article. The publication has endorsed Trump in this election cycle, and has published a series of suspect and unverified stories critical of the Texas senator, including one that Cruz accused of being fomented by Trump's "henchmen."

Cruz dismissed the Enquirer, which has leveled a series of unverified stories about Cruz's family. The Texas senator called the series of stories "idiotic."

But in the end, Cruz again refused to answer whether he would support Trump if he became the Republican presidential nominee, a prospect looking more and more likely.

More to come...