U.S. Sen. Mary Landrieu will remain on the Nov. 4 ballot in Louisiana after a state judge dismissed a lawsuit Friday that had claimed the Democrat was not qualified to run for re-election because she lives full-time in Washington.

District Judge Wilson Fields threw out the case on a technicality, ruling that Republican state Rep. Paul Hollis' lawsuit claiming the three-term senator didn't meet residency qualifications was premature.

He didn't make a decision on whether Landrieu, who owns a $2.5 million home in Washington, lives in Louisiana. Landrieu's two main Republican challengers, U.S. Rep. Bill Cassidy and tea party favorite Rob Maness, have seized on the issue this cycle as a way to portray Landrieu as out of touch. The GOP sees Landrieu's race as an opportunity to pick up one of the six seats needed to retake the Senate.

The U.S. Constitution says a senator must be an inhabitant of the state he or she represents at the time of the election. The judge said that means a challenge could be filed only after a winner is chosen by voters, in either the Nov. 4 election or the Dec. 6 runoff.

"She has not been elected, and if I read the Constitution in its plain language it says `when elected,"' Fields told Hollis and his lawyer.

Hollis said he was considering whether to appeal Fields' decision or wait until the outcome of the election to determine if he'll file another challenge. The judge ordered Hollis to pay the costs of the court case.

Landrieu's campaign hailed the decision on what it called a "frivolous lawsuit."

"For the sake of Louisiana voters, it's time we end this sideshow and focus on the issues important in this race," campaign spokesman Fabien Levy said in a statement.

Landrieu says she lives with her parents in New Orleans when in Louisiana, and she is registered to vote in Louisiana with that address. The house where Landrieu's parents live is owned by a trust in which the senator, her eight siblings and their parents share equally.

Residency criticism in 2002 and 2008 failed to unseat Landrieu, whose family has strong New Orleans roots -- her brother Mitch is in his second term as mayor and the job also was once held by their father. She has held elected office in Louisiana since 1980.

But Republicans have used the residency questions to try to define Landrieu as a Washington insider who is disconnected from her home state and too closely allied with Democratic leaders who are unpopular in Louisiana.

"Our Founding Fathers never intended for elected officials to become fixtures in Washington and become out of touch with their home state, as Sen. Landrieu obviously has," Hollis said in a statement.

Hollis' attorney, Matthew Monson, argued that Louisiana law spells out that a candidate's qualifications should be challenged within seven days of the election registration period. But when pressed by Fields, Monson agreed that "the U.S. Constitution trumps" state law.

Landrieu's lawyer, Tony Clayton, called the lawsuit a "sham," designed for a political attack against the senator. Hollis, from St. Tammany Parish, was running against Landrieu earlier this year. But he dropped out in July and threw his support to Cassidy.

Landrieu was subpoenaed to attend the hearing but didn't show up in court Friday. Clayton said she intended to attend if the case had made it to trial.