The decision by a Dane County circuit judge Thursday to toss out a lawsuit seeking to force the state to double-check voter registrations going back two years likely means a smoother Election Day, with fewer voters having to re-register at the polls and faster-moving lines, officials said.

But Attorney General J.B. Van Hollen, who filed the suit against the state Government Accountability Board in September, said not doing the checks raises the odds of voter fraud, and he vowed to appeal.

The lawsuit sought to force the accountability board to order local clerks to check hundreds of thousands of voter registrations since January 2006 against state driver, death and felon databases to ensure accuracy and comply with the federal Help America Vote Act. The suit also sought to purge ineligible voters from the rolls.

Critics said the move would throw hundreds of thousands of registrations into doubt, possibly creating a post-election ballot-counting frenzy such as that seen in Florida after the 2000 presidential election. Van Hollen maintained the checks were needed to guard against fraud that could possibly sway the presidential election.

Ruling 12 days before the election, Judge Maryann Sumi said Van Hollen failed to show that state or federal law was being violated.

"Nothing in state or federal law requires that there be a data match as a condition on the right to vote," Sumi said. "HAVA does not supplant Wisconsin's constitutionally protected right to establish its own voter eligibility standards."

Sumi also said that Van Hollen did not have standing to bring the lawsuit. The U.S. attorney general is charged with enforcing HAVA, she said, and Van Hollen should have asked the accountability board for a hearing on the matter before filing suit.

Van Hollen said he was disappointed but said he would appeal.

"We cannot lose sight of the goal of this lawsuit," Van Hollen said in a statement. "Wisconsin needs an accurate statewide voter list. Wisconsin needs to comply with state and federal laws designed to protect the right to vote. Looking the other way is not an option."

A spokesman said Van Hollen was still hopeful of a resolution before the Nov. 4 election and that the appeal, possibly directly to the state Supreme Court, would be filed soon.

Sumi also ruled Thursday that the state Republican Party has no standing to join the suit. Reince Priebus, chairman of the state party, said party lawyers would review the order and consider an appeal.

Lester Pines, a lawyer for the accountability board, called the ruling "an absolute validation."

"Judge Sumi's decision was exceptionally scholarly, well-reasoned and supported by the law," Pines said.

Van Hollen filed the lawsuit after the accountability board decided to conduct the registration checks from Aug. 6, when the state's voter database became operational.

But Van Hollen, Wisconsin co-chairman of Republican Sen. John McCain's presidential campaign, and the state GOP have argued that the accountability board should require the checks dating back to January 2006.

That was when Wisconsin was supposed to have its database up and running. Wisconsin is one of 10 states that missed that deadline, and the next to last to develop a functioning database, according to officials in those states and electionline.org, which tracks election issues.

The accountability board contended Van Hollen's suit could compel the board and local clerks to check the voting records of the nearly 1 million voters who registered between January 2006 and Aug. 5 of this year.

Most of those voters have already shown the necessary proof of residency, Barbara Hansen, director of the state voting system, has said.

But about 241,000 people who registered in person at a clerk's office, by mail or with a special deputy would not have had to show proof of residence at the time they registered, and checking those records would have been the most time consuming, Hansen said.

A check by the accountability board of voters who registered between Aug. 6 and Aug. 26 this year showed discrepancies in the information of 22 percent of the registrations. But most of those mismatches were due to transcription errors or names being recorded one way on a driver's license and another way on a voter registration card, officials said.

Local clerks said Sumi's decision will allow them to process absentee ballots and prepare for Election Day rather than check registrations that have come in since January 2006.

For voters, it means fewer of them will have to re-register on Election Day, fewer will have their eligibility challenged because of data mismatches, and voting lines will move more smoothly, some said.

"There will be less stress on the voter and less stress on the clerks," said Nancy Zastrow, the Milton clerk and president of the Wisconsin Municipal Clerks Association.