BOSTON (AP) — Massachusetts Attorney General Maura Healey is planning a legal challenge to President Donald Trump's executive order on immigration.

The Democrat is scheduled to outline her action later Tuesday. Among those joining her at the announcement will be the Massachusetts president of the American Civil Liberties Union, which filed court petitions over the weekend on behalf of people from the seven predominantly Muslim nations who were detained at airports as a travel ban took effect.

Republican Gov. Charlie Baker is not slated to attend the announcement but has signaled his support for Healey's efforts.

Healey was among 17 Democratic attorneys general who signed a letter on Sunday vowing to "fight this unconstitutional order."

Washington on Monday became the first state to file a lawsuit over the order.