U.S. District Judge John Gibney said Texas Gov. Rick Perry waited too long to challenge Virginia's requirements, The Hill reported. Perry filed the lawsuit in December, arguing the state law that petitions must be circulated by registered or qualified voters in the state is unconstitutional.
"The commonwealth is far along in the electoral process," the judge said. "The primary election is so close [March 6] that the plaintiffs cannot gather the requisite signatures to get on the ballot. To place the plaintiff on the ballot would deprive Virginia of its rights not only to conduct the primary in an orderly way but also to insist that a candidate show broad support."
Virginia requires 10,000 valid signatures for candidates in a primary. Gibney's ruling also affects former House Speaker Newt Gingrich, former Utah Gov. Jon Huntsman and former U.S. Sen. Rick Santorum.
Romney, who served one term as governor of Massachusetts, appears to be the front-runner for the Republican nomination after what was effectively a tie with Santorum in Iowa and a sizable win in New Hampshire. Paul, a libertarian congressman from Texas, finished third in Iowa and second in New Hampshire.