Hawaii is among the 22 states — so far — whose attorneys general quickly signed on to a lawsuit Tuesday to challenge President Donald Trump’s executive order against birthright citizenship.

Among the slew of immigration-related executive actions the new president signed on Day 1, this order drew a most vigorous rebuke. It aims to roll back birthright citizenship by ordering U.S. agencies to refuse to recognize the citizenship of children born in the U.S. if neither mother or father is a U.S. citizen or legal permanent resident. The states’ AGs argue that violates the U.S. Constitution’s 14th Amendment, which provides that anyone born in the U.S. is considered a citizen.