Civil rights groups asked a federal court Monday to let them defend against a lawsuit over voter rolls in the Philadelphia suburbs.

The lawsuit was brought two weeks ago by Judicial Watch, a conservative activist group known for its public-records requests and litigation. The group claims Bucks, Chester, and Delaware Counties have failed to properly remove voters who have become ineligible. It seeks the removal of an unspecified number of voters according to unspecified criteria.

“Lawsuits like these are designed to force counties to pull eligible voters off the rolls, and that’s just not the way democracy is supposed to work,” said Suzanne Almeida, interim executive director for Common Cause Pennsylvania.

The group, along with the League of Women Voters of Pennsylvania, filed a motion Monday to intervene in Judicial Watch v. Pennsylvania. They are represented by the Lawyers’ Committee for Civil Rights Under Law, the state and national ACLUs, and New York-based Simpson Thacher & Bartlett LLP.

Judicial Watch has gone after voter rolls across the country, accusing elections officials of violating the National Voter Registration Act by not removing voters who have become ineligible, such as those who have moved.

“This isn’t our first rodeo,” Judicial Watch president Tom Fitton said last week. "And Pennsylvania has a big issue. This will be a statewide issue in theory if we’re able to get the results we want. Every county will be subject to having to follow the rules.”

In the Pennsylvania suit, the group sued the three counties and the state, raising the specter of fraud without providing any evidence. (In-person voter fraud is rare.)

Judicial Watch said the three Pennsylvania counties removed only 17 voters in 2017 and 2018, citing a national election administration survey. In fact, officials said, they removed tens of thousands of inactive voters.

“We 100% dispute” the claims, Secretary of State Kathy Boockvar recently told state lawmakers.

Almeida said the voting rights groups are hoping to have the suit dismissed. If the court does end up ordering counties to remove voters, she said, the groups want to play a role in making sure it’s done as fairly as possible.

Voter roll maintenance is a normal part of election administration, and in Pennsylvania, voters who do not vote in multiple elections are mailed a postcard asking whether they want to stay active. Only after about eight years of not voting and no response are voters removed from the rolls.

Large-scale purges of voter rolls can remove eligible voters who planned to vote in future elections, disenfranchising them, and can disproportionately affect low-income voters and people of color, experience and studies have shown.