Republicans are challenging extended mail ballot deadlines in at least two states in a legal maneuver that could have widespread implications for mail voting ahead of this year’s presidential election.

A lawsuit filed last week in Mississippi follows a similar one last year in North Dakota, both brought in heavily Republican states before conservative federal courts. Democratic and voting rights groups are concerned about the potential impact beyond those two states if a judge rules that deadlines for receiving mailed ballots that stretch past Election Day violate federal law.

They say it’s possible such a decision would lead to a nationwide injunction similar to one last year when a Texas judge temporarily paused the FDA’s approval of the abortion pill mifepristone.

“This effort risks disenfranchising Mississippi voters, but we don’t want that to also be precedent for other states,” Abhi Rahman, communications director of the Democratic Legislative Campaign Committee, said in response to the most recent lawsuit.