Donald Trump: Ted Cruz Should Go to Court to Prove He Can Be President

Donald Trump continues to goad Ted Cruz over his birthplace, Canada, arguing that if Cruz becomes the Republican nominee for president he will face a legal battle with Democrats over his eligibility for the office. REUTERS/Brian Snyder

The spat between GOP presidential candidates Donald Trump and Ted Cruz over whether the junior U.S. senator from Texas is eligible to become president intensified Thursday. The two took their arguments to cable news, with Trump claiming that Cruz's birth in Calgary, Canada, could pose a problem for the Republican Party if he becomes its nominee.

In an interview with CNN 's Wolf Blitzer, Trump reiterated his claim that if Cruz becomes the nominee, he could face a yearlong legal battle with Democrats over his eligibility for the office. "How do you run against the Democrat, whoever it may be, and you have this hanging over your head if they bring a lawsuit?" Trump asked.

On Twitter, the New York real estate mogul offered Cruz some "free legal advice," suggesting he should settle the issue with a judgment from a court. "[Y]ou will win!" Trump tweeted.

.@SenTedCruz Ted--free legal advice on how to pre-empt the Dems on citizen issue. Go to court now & seek Declaratory Judgment--you will win!

— Donald J. Trump (@realDonaldTrump) January 7, 2016

"I'm doing this for the good of Ted," Trump added.

Cruz, who was born to an American mother and Cuban father, defended himself to CNN's Dana Bash. "Listen, the Constitution and the laws of the United States are straightforward," he said. "The very first Congress defined the child of a U.S. citizen born abroad as a natural-born citizen."

Most experts agree that the issue is cut-and-dried. Cruz cited Barry Goldwater, George Romney and John McCain as examples of presidential candidates who were born outside the country. But, in a shift in tone, McCain told a Phoenix radio interviewer Wednesday that he believes being born on "foreign soil" is different from being born in a U.S. territory, which the Panama Canal Zone was in 1936 when McCain was born there.

"I am not a constitutional scholar on that, but I think it's worth looking into. I don't think it's illegitimate to look into it," McCain said.

McCain is no fan of Cruz's and notably called the Texas senator a "wacko" in 2013. Cruz shot back this week that McCain's position is designed to help Cruz's Republican rival Marco Rubio.

"I think it is no surprise to anybody that John McCain is going to be supporting Marco Rubio in this election," Cruz told Bloomberg. "It's no surprise at all that he's trying to do what he can to help the candidate that he's favoring who he thinks shares policy positions with him."

Meanwhile, at least one Democratic lawmaker is backing up Trump's claims, saying that he is poised to challenge Cruz if he becomes the Republican nominee. U.S. Representative Alan Grayson of Florida told U.S. News and World Report that he believes Cruz's mother, Eleanor, may have renounced her U.S. citizenship by taking a Canadian oath of citizenship.

"The Obama birthers are loons," Grayson said. "There's no plausible legal argument that Obama is not qualified to be president; that's ridiculous. There's a very good legal argument that Ted Cruz is not qualified to be president."