Though President Donald Trump has not yet ruled out a pardon for former campaign chairman Paul Manafort, Judge Andrew Napolitano warned he should tread lightly.

During a Fox & Friends interview Tuesday, the legal expert argued that as it stands, it’s unlikely the commander in chief can save Manafort, as he’s facing federal and state charges. For that reason, the judge said, “if he’s pardoned, the day of the pardon, he will be indicted by the states” for the crimes to which he’s already pleaded guilty.

But there’s a catch. That scenario only holds if a new interpretation of the double jeopardy rule isn’t implemented.

As Napolitano explained, a case currently before the Supreme Court involving an Alabama man prosecuted twice under federal and state law for the same offense could change things. That’s because the defendant, Terance Gamble, argued that’s a violation of the double jeopardy clause, and it appears he may have some support.

Napolitano expressed his surprise at the reconsideration of the longstanding rule, noting “it has been 150 years since they last examined whether or not the double jeopardy clause prohibits the two different sovereigns” from indicting an individual for the same crime. However, he contended that Gamble’s argument interprets the rule “as the framers intended it.”

That could mean good news for Manafort, who might then be able to escape state charges, but Napolitano doesn’t think a ruling on the key case will come before April.

Watch the clip above via Fox News.

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