With Republicans threatening to reverse LGBTQ civil rights and generally undermine democratic elections, there’s a lot riding on the November midterms. But Voter ID laws across the nation could seriously impair transgender people from voting.

New research from The Williams Institute found that out of 878,300 eligible transgender voters in the U.S., as many as 203,700 could be blocked from voting because their government-issued IDs don’t reflect their gender identity — that’s nearly one-fourth of all eligible trans voters.

If a trans person arrives at a polling place with a government-issued ID containing an incorrect gender or name, they may be turned away by poll workers who think they’re trying to “impersonate” another individual.

203,700 disenfranchised trans voters is roughly the entire population of Salt Lake City, Utah; Little Rock, Arkansas; Amarillo, Texas; or Grand Rapids, Michigan, according to U.S. Census data.

Changing an ID isn’t always easy, and “transgender people of color, young adults, people with low incomes, and people with disabilities are more likely to not have accurate IDs for voting,” the Williams Institute wrote.

Trans people face numerous barriers to changing their ID gender markers. The process can take lots of time and money and require access to medical care that many trans people don’t have.

According to the Movement Advancement Project, 10 states require documentation from a medical provider in order to change a trans person’s gender marker; 8 states require proof of surgery, court order, or an amended birth certificate; and 10 states have “burdensome” or “unclear” policies on changing such gender markers.

Changing a birth certificate to get a new ID can also present problems: 12 states require trans people to undergo a gender-affirming surgery before officials will revise a birth certificate; 4 states don’t allow any changing of birth certificate gender markers whatsoever.

Name changes aren’t always easy either. Nine states require people to publicly post their name change requests online, something that can make them a target for harassment or violence.

An estimated 414,000 eligible trans voters live in the 31 states that predominantly have in-person voting and require voter ID. Nearly half of trans voters in those states don’t have an ID that accurately reflects their gender or name. Additionally, 64,800 eligible trans voters live in states that have very strict voter ID laws.

The exclusion of trans voters is particularly concerning as Republicans introduce anti-trans legislation across the country.

Republicans have ostensibly introduced voter ID laws as a way to stop the nearly nonexistent problem of voter fraud. But both the American Civil Liberties Union and The Brennan Center for Justice have called voter ID laws a form of “voter suppression” that mostly disenfranchises Democratic voters.