The Democratic National Committee is suing New Hampshire officials over a Republican-backed election law that it claims will disenfranchise voters and have a chilling effect on key members of the party’s base in 2024.

The challenge, which was shared first with POLITICO, takes on a law passed last year that requires people who register and vote on Election Day without a photo ID to send in missing documentation to the state within seven days.

If they don’t, their votes will be thrown out and they’ll be referred to the state Attorney General’s office.

President Joe Biden’s campaign is backing the lawsuit. Senior officials on the team said they are concerned the legislation could affect critical voting blocs in the battleground state in the 2024 election, especially young people, college students and low-income voters.

“President Biden and Vice President Harris believe that we should be making it easier, not harder, for every eligible American voter to participate in our democracy. New Hampshire’s law flies in the face of that belief, and is a chilling and unacceptable embrace of the election fraud hysteria championed by Donald Trump,” said Biden campaign manager Julie Chavez Rodriguez. “In an election that could very well determine the fate of our democracy, it is our imperative to fight for the right to vote. This is just the beginning.”

Biden campaign officials said that 75,000 voters in New Hampshire registered in person and voted on Election Day in 2020. It is not clear how many of those people registered without an ID, since at the time, those voters could still cast a regular ballot as long as they filled out a form that attested to their identity.

But a senior Biden campaign aide, who was granted anonymity to discuss a pending legal issue, said the team anticipated that “thousands” of voters could be impacted by the new law.

This is the second lawsuit this year filed by the DNC challenging what the party saw as a law that makes it harder for people to vote, following a suit in October involving North Carolina legislation.

Top Biden campaign officials said a key part of their legal strategy in 2024 will be taking on voting laws they say are overly restrictive — and, crucially, can be litigated and resolved before the November election. Republicans nationally have defended more stringent measures as necessary to prevent rare cases of voter fraud.

New Hampshire Secretary of State David Scanlan defended the law in a statement: “We know from our experience requiring all voters to present an ID in order to obtain a ballot when they check-in at the polls, that only a small fraction of a percent do not have an acceptable form of ID. The very few voters affected can still vote after completing an affidavit.”

Biden campaign officials said the suit in New Hampshire is aimed at winning relief ahead of the general election, not the primary, where Biden is facing a challenge from Rep. Dean Phillips (D-Minn.).