The slim Republican majority in the House just got slimmer.

Democratic state Sen. Timothy Kennedy on Tuesday won the special election for the New York congressional seat vacated by a retiring Democrat, further narrowing the GOP’s slender majority in the House.

Kennedy comfortably defeated his Republican opponent Gary Dickson in the race for the Buffalo-area district seat by a margin of more than 36 percentage points, according to the Associated Press. When Kennedy is officially sworn in to succeed the retiring Brian Higgins, the GOP House majority will be cut to 217-213, affording Speaker Mike Johnson just a single vote to spare on partisan issues.

Republicans will nevertheless take comfort from three upcoming special elections in the next two months for vacant GOP seats, including in the California district most recently held by former House Speaker Kevin McCarthy.

Kennedy, who has served in New York’s state Senate since 2011, said he plans to focus on immigration and reproduction rights. He also wants to toughen gun laws, and previously campaigned in the state Senate for new firearm safety legislation in the wake of a white supremacist mass shooting at a Buffalo supermarket in 2022.

“We need to elect pro-democracy, anti-MAGA candidates all around the country this November,” Kennedy said in a victory speech, “And it starts here in this room in Buffalo, New York, tonight.”

Kennedy will serve the remainder of Higgins’ unexpired term. Higgins, 64, resigned in February and is now the president of a performing arts center. While announcing his intention to step down during his tenth term in office, Higgins said he had grown frustrated with dysfunction on Capitol Hill.

“Congress is not the institution that I went to 19 years ago. It’s a very different place today,” he said at a news conference in December, according to the AP. “We’re spending more time doing less. And the American people aren’t being served.”

Kennedy was widely expected to win in the district, where Democrats outnumber Republicans by a ratio of over two-to-one. He also massively outspent his GOP opponent, pouring a little over $1 million into the race compared to the $21,068 spent for Dickson.

Kennedy’s victory also follows his fellow Democrat Tom Suozzi’s special election victory in February for the New York district vacated by former GOP Rep. George Santos, who was expelled from Congress.