MEDIA, Pa. (WPVI) -- The issue of voter fraud has become part of the political conversation this year, with complaints and warnings coming primarily from the Republican side of the coin.Thursday morning, Congressman Patrick Meehan called for United States Attorney General Loretta Lynch to launch an investigation of FieldWorks LLC.FieldWorks bills itself as a Democratic Grassroots organization.State Police raided its Delaware County office earlier this week, looking for evidence of voter registration fraud.Meehan and other local Republicans question whether roughly 7,000 registrations were submitted by the Oct. 11 deadline and other irregularities."What do you do about the 52 registrations in which there's no valid address? It's not that there's no valid address. There's an address listed. There's just no such location in Delaware County," said Meehan.FieldWorks denied any wrongdoing in a statement to Action News, and said it's cooperating with investigators.Meehan's opponent for the 7th Congressional District, Mary Ellen Balchunis, says she's never heard of FieldWorks, and said she was unaware of the investigation."I believe this is part of the Republican effort to suppress voter turnout," said Mary Ellen Balchunis.Congressman Meehan denied the claim.David Thornbugh is president of the Committee of Seventy, a government watchdog group.His message: Just tune it out and vote."The candidates and parties trying to leverage just a few votes here and there. It's hard to tell what exactly is going on with these investigations," said Thornbugh.