New Hampshire Gov. Chris Sununu (R)

In a surprise outcome, New Hampshire's Supreme Court dealt a major blow to voting rights in the Granite State when it issued an advisory opinion saying that a Republican-backed bill to tighten voter residency requirements doesn't violate the state constitution. One of the court's three Democratic-appointed justices sided with the two GOP appointees in the ruling, paving the way for Republican Gov. Chris Sununu to sign the bill into law, which he did on Friday.

As we’ve detailed, this law requires New Hampshire voters to have legal "residency" in the state and not just simply make it their "domicile," or the place where they live day to day. Becoming a resident under the legal definition requires actions like registering a car in-state and obtaining an in-state driver's license. Effectively, this new requirement is a thinly disguised poll tax on Democratic-leaning college students from other states, who are unlikely to go to the expense and trouble of becoming legal residents even if they live in New Hampshire full-time. The law therefore will likely lead to fewer college students voting in the Granite State.

The state Supreme Court’s decision was unexpected because the state constitution provides an explicit guarantee of voting rights for all citizens who are "inhabitants" of the state, not just those who fulfill the requirements of legal residency. Indeed, in 2015, the Supreme Court unanimously struck down a very similar GOP-supported law.

A federal lawsuit now appears to be the only option left for opponents. Plaintiffs could argue that the law violates the 24th Amendment's ban on poll taxes or the 1979 U.S. Supreme Court ruling Symm v. United States that guaranteed college students the right to vote at their schools if they live there. However, Democrats may not fare much better now that partisan Republicans extremists are poised to take a majority on the high court.

This story has been updated.