Transgender athletes in Connecticut scored a legal victory. The 2nd U.S. Circuit Court of Appeals affirmed a Connecticut rule allowing transgender athletes to play on teams that reflect their gender identification: Meaning a male-to-female transgender athlete is allowed to compete against cis-gendered women.

The decision upheld the result from a lower court and sets up a potential Supreme Court battle.

Transgendered athletes in sports have always been controversial but the backlash picked up steam when Lia Thomas, a University of Pennsylvania swimmer started finding success in women’s swimming after transitioning.

Liberals have argued that transgender athletes should have the right to compete as their assumed gender. Conservatives argue that biological males competing against biological women can undermine fairness.

Many states as well as some governing sports bodies have already passed their own laws or policies barring transgender females from participating in women’s sports. Some places have used Title IX as a shield to protect transgender athletes but in the event such a case makes it to the U.S. Supreme Court the current balance of the bench would favor conservatives.