Rep. Mike Gallagher, R-Wis., chairman of the House select committee on China, announced he’s leaving Congress on April 19 – which will temporarily leave House Republicans with just a one-seat majority.

Gallagher revealed in February that he would not be running for a fifth term in the House, a shocking announcement for someone long considered a rising star within the Republican Party. 

His early departure will mean that Speaker Mike Johnson, R-La., can only afford to lose one GOP lawmaker on any vote that falls along party lines. That will likely remain the case until May 21, when there’s a special election to replace ex-Speaker Kevin McCarthy, R-Calif.