Saying illegal Wisconsin votes could sway the presidential election, Attorney General J.B. Van Hollen has sued the state elections agency to force ineligible voters off the rolls.

But election experts warned that if the Justice Department lawsuit is successful, eligible voters could be disenfranchised and the state could face a post-election ballot-counting frenzy similar to Florida's after the 2000 presidential race.

"You shouldn't penalize the voter because you've got mistakes in your database," said Dan Tokaji, an election law expert at Ohio State University. "That's the absolute worst thing to do."

The suit filed in Dane County Circuit Court on Wednesday is believed to be the only one of its kind in the country, according to Tokaji and other national election experts.

In it, Van Hollen asks the court to force the Government Accountability Board to check voter registrations for accuracy dating back to Jan. 1, 2006, when the state was supposed to be in compliance with the federal Help America Vote Act.

But the state missed that deadline and Van Hollen argues new voters were able to register without undergoing the federally required accuracy check.

The board said last month that it had finally reached compliance with the law, which is designed to ensure that only eligible voters' ballots are counted at the polls. The board also said it would only check new registrations for accuracy dating to Aug. 6.

But Van Hollen said limiting the checks — in which information contained in the board's voter registration database is compared for accuracy against information held by other state agencies — to those occurring within the last few weeks

instead of years means "a significant risk, if not a certainty" that illegal votes will be counted.

"Because of the (board's) inaction, properly qualified voters are at risk of having their votes diminished and diluted by the votes of unqualified, ineligible voters who are not entitled to cast ballots," the suit said.

That could affect whether Democratic Sen. Barack Obama, of Illinois, or Republican Sen. John McCain, of Arizona, wins the state's 10 electoral votes — and even the presidency, Van Hollen said in the suit.

'The next Florida'

But critics said a successful lawsuit could require anyone whose information in the state voter database doesn't match information maintained by other agencies to cast provisional ballots, which are difficult to count.

"If you have a large number of provisional ballots, it exponentially increases the possibility for a post-election fight, and Wisconsin could easily become the next Florida," Tokaji said.

Van Hollen spokesman Kevin St. John said voters won't be disenfranchised if the suit is successful because the federal law "contains many safeguards that allow a qualified voter to cast a ballot and have that vote counted." Van Hollen simply wants the federally mandated checks carried out and isn't asking for the automatic use of provisional ballots by voters whose information doesn't match in the checks, St. John said.

Kevin Kennedy, the accountability board's executive director, said in a statement that Van Hollen, a Republican, is asking the court to force the board to adopt a position pushed by the state GOP and that conducting checks going back to January 2006 could create "unnecessary hardship and confusion at the polls, and at worst, the disenfranchisement of Wisconsin citizens with a clear and legitimate right to vote."

Failed matches

The board last month found that information contained on more than 20 percent of recent voter registrations failed to match information maintained on state Department of Transportation records such as names and addresses, mostly because of variations in how a name was used, typographical errors or incompatibilities in the two agencies' databases. Even information from four of six Accountability Board members in the voter database failed to match DOT records.

Mark Jefferson, executive director of the state GOP, said, "The Government Accountability Board is not taking the HAVA law seriously. Thankfully, the attorney general is."

Joe Wineke, chairman of the state Democratic Party, said the suit is a "cynical attempt to disenfranchise voters" and part of a GOP pattern to "distract and deny voters with fearmongering."

Mark Pitsch can be reached at mpitsch@madison.com or 608-252-6145. Jason Stein can be reached at jstein@madison.com or 608-252-6129.