Sen. Rand PaulRand PaulDems blast Trump plans for deep spending cuts Trump team prepares dramatic cuts Paul, Lee call on Trump to work with Congress on foreign policy MORE (R-Ky.) is calling 2016 White House rival Sen. Ted CruzTed CruzBooker is taking orders from corporate pharmaceuticals Caitlyn Jenner to attend Trump inauguration: report Trump’s UN pick threads needle on Russia, NATO MORE (R-Texas) a "natural-born Canadian" and saying the Supreme Court may need to weigh in on his eligibility for the presidency.
"I think without question, everybody would accept that, you know, Cruz is a natural-born Canadian, that he was naturally born there," Paul said in an interview on Fox News on Monday.
The Kentucky senator clarified that he wasn't calling into question Cruz's citizenship, saying that the constitutional requirements for holding executive office are more ambiguous than those for becoming a citizen.
"The only part of the Constitution that says 'natural-born' is with regard to the president. So it appears to be a unique qualification, and most people have interpreted they have to be born in the U.S. until recently.
"I think the Democrats are going to force it to be adjudicated, and I think the Supreme Court is going to have to decide it," he added.
Cruz was born in Canada to an American mother and a Cuban father, leading GOP rival Donald Trump to raise questions about his eligibility for the White House.
Rep. Alan Grayson (D-Fla.) has also vowed to file a lawsuit challenging Cruz's eligibility if the senator and Iowa front-runner wins the GOP nomination.
Cruz made the case for his eligibility for president on Sunday, saying any legal questions had been settled.