CHICAGO (AP) — As President Joe Biden and Donald Trump step up their campaigning in swing states, a quieter battle is taking place in the shadows of their White House rematch.

The Republican National Committee, newly reconstituted under Trump, has filed election-related lawsuits in nearly half the states. Recent lawsuits over voter roll maintenance in Michigan and Nevada are part of a larger strategy targeting various aspects of voting and election administration.

It’s not a new strategy. But with recent internal changes at the RNC and added pressure from the former president, the legal maneuvering is expected to play an increasingly significant role for the party as Election Day in November approaches. The lawsuits are useful for campaign messaging, fundraising and raising doubts about the validity of the election.

Danielle Alvarez, a senior adviser to the RNC and the Trump campaign, said the lawsuits were one of the organization’s main priorities this year.

“This is something that’s very important to President Trump,” she said. “He has said that this is something the RNC should do year-round.”