U.S. Sen. Raphael Warnock's campaign and Democratic groups are suing the state of Georgia to overturn guidance by Republican Secretary of State Brad Raffensperger that counties can't offer Saturday voting ahead of next month's Senate runoff election.

Sens. Raphael Warnock (left) and Jon Ossoff, D-Georgia. (Courtesy photo) Sens. Raphael Warnock (left) and Jon Ossoff, D-Georgia. (Courtesy photo)

The lawsuit, filed late Monday by the Democratic Party of Georgia, Democratic Senatorial Campaign Committee and the Warnock campaign, challenges the state's finding that it would be illegal to hold early voting on Nov. 26, the day after a state holiday. The lawsuit says the state's interpretation hurts Warnock in particular because Democrats tend to push early voting more than Republicans.