The legal travails of President Bill Clinton may soon haunt President Trump.

A New York appeals court on Thursday ruled that Mr. Trump, like Mr. Clinton before him, is not protected by the presidency from answering civil charges. The five-judge panel in Manhattan said that the Constitution’s supremacy clause does not bar state courts from hearing claims over “alleged unofficial misconduct” — that is, claims of improper or illegal action before a president took office. The decision expands on the precedent set in Clinton v. Jones, in which a unanimous Supreme Court in 1997 ruled that a federal court had jurisdiction over a sexual harassment lawsuit filed by Paula Jones, a former low-level Arkansas state employee, against Mr. Clinton.

Yes, the presidency is important and its occupant may have important duties to attend to other than to produce documents or sit for depositions in a civil suit alleging sexual misconduct and defamation, the court explained, but “the President is still a person, and he is not above the law.”

Two judges dissented, observing that the threat of contempt, should Mr. Trump resist the legal process, would put a state court in “direct control” over the president.

A former contestant on Mr. Trump’s reality TV show “The Apprentice,” Summer Zervos went public during the 2016 campaign with accusations that Mr. Trump kissed and groped her without her consent. She is suing the president for defaming her shortly after she came forward, calling her charges a “hoax.” She filed her suit days before Mr. Trump took the oath of office.