Donald Trump. Photo: Gage Skidmore.

ABC – Donald Trump called Sen. Ted Cruz an “unstable person” and a “liar” and threatened to sue him over his eligibility to be president if he didn’t “take down his false ads and retract his lies” in recent statements.

But Cruz fired back, saying the real estate mogul “apparently lost it,” shouting “liar, liar” like a grade school student and claimed that “internal poll numbers in South Carolina must be plummeting following that debate.”

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