House Majority Leader Eric Cantor has lost Virginia’s Republican primary in one of the biggest upsets in congressional history. Cantor fell to tea party challenger David Brat, whose campaign accused Cantor of being insufficiently right-wing. Cantor conceded the race before supporters Tuesday night.

Rep. Eric Cantor: “I know there’s a lot of long faces here tonight, and it’s disappointing, sure. But I believe in this country. I believe there’s opportunity around the next corner for all of us. So I look forward to continuing to fight with all of you for the things that we believe in, for the conservative cause, because those solutions of ours are the answer to the problems that so many people are facing today.”

The House’s second most powerful Republican, Cantor’s defeat could upend Republican politics while further endangering congressional passage of immigration reform. Brat ran on a staunch anti-immigrant platform, citing Cantor’s mild support for a version of the DREAM Act. It’s the first time a House majority leader has lost a primary since the position was created in 1899.