U.S. District Judge William Zloch said Florida has a “compelling interest” to ensure that non-citizens do not cast ballots. Zloch rejected a challenge from several voting rights groups and the Obama administration. They contended the purge violated a federal law against removing voters within 90 days of an election.

Zloch, however, said the law “does not require the state to idle on the sidelines until a non-citizen violates the law before the state can act.” Along similar lines, a federal judge ruled in June that the 90-day prohibition does not apply to people who are not U.S. citizens.

Secretary of State Ken Detzner said Florida has an obligation to ensure Florida’s voter rolls are current and accurate, which means removing ineligible voters when they are identified.

The state’s original purge list contained more than 2,600 names but was beset by inaccuracies. Last month, a revised list of 198 names of possible non-citizens was produced through use of a Homeland Security Department citizenship database. State officials asked elections supervisors to remove those names from the rolls but most said the process would run past the Election Day.

Voting registration is being closely watched because Florida is a key swing state in the presidential election.

One of the groups that tried to stop the purge said Zloch’s ruling could prevent legitimate votes from being cast.

“Removing individuals this close to the election could jeopardize the right to vote for eligible citizens that ended up on the voter purge list due to faulty matching programs,” said Ben Hovland, senior counsel at the Fair Elections Legal Network.