CHICAGO (AP) — The debate over whether Canadian-born Ted Cruz is eligible to be president is moving from the campaign trail to the courtroom.

Lawsuits challenging the Texas Republican’s eligibility for the ballot have been filed in states including Illinois, New York and Alabama.

Fellow GOP candidate Donald Trump also has threatened to sue over the issue.

Cruz and some legal experts say he’s eligible because his mother was a U.S. citizen when he was born.

The Illinois plaintiff is pharmacist and lawyer Lawrence Joyce. He says he fears if Cruz becomes the GOP nominee, Democrats will get him kicked off the ballot in some states or Cruz will be forced to drop out and Republicans will replace him with a moderate candidate.

Joyce says he’s backing Ben Carson but is acting independently.