A fiercely contested bill to make residency a condition of voting in New Hampshire was determined by the state Supreme Court to be constitutional Thursday, in a major ruling that clears its approval by Gov. Chris Sununu.

In a 3-2 ruling, the court found that the bill, House Bill 1264, is not a burden on the right to vote, but rather a means to better organize state laws “in order to place voters and residents on equal footing as New Hampshire citizens.”

The court’s decision, which came without warning, now sets up a high-stakes choice for Sununu. On Thursday afternoon, hours after the court weighed in, the bill passed from Senate President Chuck Morse’s desk over to the governor’s office. That set in motion a constitutionally mandated five-day countdown; Sununu must decide by Tuesday whether to veto, sign or let pass without signature a law he has taken varying positions on in the last seven months.

In a terse statement Thursday, Sununu declined to show his cards.

“We appreciate the time and consideration given to this matter by the New Hampshire Supreme Court and are reviewing their decision,” he said.

The law represents a simple linguistic change that to supporters and detractors could have vast effects.

Currently, people voting in New Hampshire need only demonstrate that they are domiciled in the state, a status that requires voters count New Hampshire as their place of residence “more than any other place,” but which doesn’t carry the requirements of residency. HB 1264 would merge the definitions of “residency” and “domicile” in New Hampshire law, effectively making anyone who casts a ballot in an election a de facto resident.

Republican supporters of the bill have called the move a common-sense change that brings New Hampshire in line with 49 other states that require residency to vote. But Democrats and voting rights groups have attacked the bill as a voter suppression technique aimed at college students, arguing that the resulting requirement for voters to obtain New Hampshire driver’s licenses and car registrations amounts to a “poll tax.”

Faced with increasing pressure both to sign and to veto the bill, Sununu and the Executive Council asked the Supreme Court in May to review the bill’s constitutionality, specifically. The request asked justices to wade into two areas: Whether the overall bill is, on its face, constitutional, and whether its specific application to college students would also be constitutional. The request centered on the equal protection clauses of both the state and federal constitutions, as well as Article 11 of the state Bill of Rights, aiming to determine whether the bill would unlawfully suppress student votes.

In an 18-page ruling Thursday, Chief Justice Robert Lynn and Justices Anna Barbara Hantz Marconi and Patrick Donovan found that rather than suppressing the voting rights of college students, the bill would instead mandate that they choose between making New Hampshire their voting home, and meeting the vehicle registration requirement, or keeping their residence in their state of origin and forgoing their ability to vote.

“There is nothing unfair or unconstitutional about state laws that require persons to make this choice,” the justices wrote. Two other justices – Justice Gary Hicks and Justice James Bassett – declined to join the majority, ruling that not enough is known about the effect of the bill to weigh in on its constitutionality.

The ruling clears the way and provides cover for Sununu to sign the bill after a notable political evolution. In a secret video recording by voting rights activists released in December, Sununu said that he “hated” the bill, that it would likely not survive legal scrutiny, and that he wished the Legislature would kill it. But after the release of the video, the governor spent months deflecting questions on his support for the bill, telling reporters he was awaiting the final language.

On April 24, asked about HB 1264 and its near-identical companion House Bill 372, a spokesman for the governor, Ben Vihstadt, released the clearest public statement on the governor’s decision, saying that the governor had “serious concerns” with both bills and “does not support either bill in their current form.” But the governor has softened his position, and he recently indicated on a Boston radio program that he will sign HB 1264 if the Supreme Court upholds its constitutionality.

On that program, the Howie Carr Show, Sununu gave the clearest picture of his feelings on the bill.

“So what I did is I’ve taken that bill, I’ve sent it to the Supreme Court, I say, ‘Give us your opinion on it,’ ” he said in an interview June 20. “So that assuming they come back and it’s affirmative and they assure that it’s constitutional, we can sign the bill with I think great confidence that we’re protecting the integrity of the system, we haven’t violated any constitutional rights, and finally New Hampshire’s laws are kind of up to par with everybody else.”

Opponents of the bill have vowed to rally outside Sununu’s office Friday morning, fearing the governor will move to sign it that day.

(Ethan DeWitt can be reached at edewi tt@cmonitor.com, or on Twitter at @edewittNH.)