Republicans‘ uphill climb of impeaching President Joe Biden got a little steeper following Rep. Ken Buck‘s (R-CO) early retirement announcement, with his departure presenting the House GOP with significant math problems.

Buck will leave Congress on March 22, handing Republicans just a two-seat majority over Democrats, likely posing a problem for the divided GOP conference. A lawmaker told Axios in February that there are already “easily 40-50” Republicans who are likely to vote against the impeachment.