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Donald Trump continues to raise the issue of Sen.Ted Cruz's (R-Texas) American citizenship. 

In a Fox News Sunday interview (below), Trump argued that the Canadian-born senator must "get this problem solved" before potentially running against a Democrat in the fall and facing a lawsuit.

"Does 'natural-born' mean born to the land, meaning born on the land? In that case, he's not. But nobody knows what it means because it hasn't been adjudicated and it hasn't gone to the Supreme Court," said Trump. 

On America's Newsroom this morning, Fox News senior judicial analyst Judge Andrew Napolitano said that Cruz's American citizenship is "well-settled and established" under a law that goes back 100 years.

Napolitano said Cruz's citizenship cannot be questioned, since his mother was an American citizen when he was born. 

"A human being born in another country with at least one parent who is an American citizen, who lived in the United States for at least one year during the parent's life before the birth, is an American citizen. That is exactly Ted Cruz's situation. ... [He] is a natural-born American citizen," Napolitano explained.

He agreed with Martha MacCallum that the reason for bringing this up is "political," not legal, since many voters may not know the law. 

Napolitano said Cruz could benefit from getting this cleared up now, rather than later. But he noted that Trump is correct that the Supreme Court has never reviewed the law "because the issue has never come up."

Watch the judge's full analysis above.

Don't miss the Fox Business Network Republican Debates on Thursday, January 14th, starting at 6:00pm ET. If you're unsure of where to watch FBN in your area, go to the Channel Finder.

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