The Republican Party’s hold on the House majority suffered a massive blow on Wednesday when House Speaker Paul Ryan, R-Wis., announced plans to retire from Congress upon the conclusion of his current term.

While Ryan will remain House speaker until he leaves, sources said the announcement is damaging for party morale and could encourage more Republicans to head for the exits, especially since he revealed his decision just seven months before a midterm that was already poised to sweep Democrats into power. Worse, Ryan is a prolific fundraiser, and his announcement this close to November jeopardizes House Republicans’ access to the resources they need to withstand gale-force political headwinds generated by dissatisfaction with President Trump.