WASHINGTON (JTA)-Rep. Eric Cantor, the majority leader in the U.S. House of Representatives and the highest-ranking Jew in congressional history, lost his Republican primary in Virginia to a Tea Party challenger in a major upset.

Cantor, 51, who rode the Tea Party wave to majority leader after the 2010 elections, was trailing Dave Brat, 56 to 44 percent, with 87 percent of the vote counted on Tuesday evening, June 10. Cantor conceded after 8 p.m.

"Obviously we came up short," Cantor told his stunned followers in a Richmond hotel ballroom. "Serving as the 7th District congressman and having the privilege of being majority leader has been one of the highest honors of my life."

"I know there's a lot of long faces here tonight," The Washington Post quoted Cantor as saying to supporters in his Richmond district. "It's disappointing, sure. But I believe in this country. I believe there's opportunity around the next corner for all of us."

"We're all processing it," said Matt Brooks, the president of the Republican Jewish Coalition. "He was an invaluable leader, he was so integral to the promotion of, to congressional support of the pro-Israel agenda. It is a colossal defeat not just for Republicans but for the entire Jewish community."

In a statement, Nathan Diament, executive director for public policy of the Orthodox Union, called Cantor a friend who has "been a critical partner for the advocacy work of the Orthodox Jewish community on issues ranging from Israel's security and the security of Jewish institutions in the United States, to religious liberty to educational reform, and opportunity to defending the needs of the nonprofit sector."

Brat, an economics professor, depicted Cantor as pivoting away from conservatism, most prominently in leaning toward some immigration reforms.

Cantor, while keeping an immigration reform package from reaching the House floor, has said that he favored some of its elements, including a path to citizenship for immigrants who arrived in the United States illegally as children. Brat accused Cantor of dithering and emphasized secure borders as his immigration policy.

The Washington Post reported that less than 24 hours after losing the primary, Cantor announced that he will resign as leader July 31, but keep his seat until his term ends in January.

"While I may have suffered a personal setback last night, I couldn't be more optimistic about the future of this country," Cantor told reporters Wednesday afternoon. "I'm honored that I've had the privilege of serving the people of Virginia's 7th District."

Speaker John A. Boehner (R-Ohio) led a Wednesday afternoon meeting of the House Republican conference and thanked Cantor and his staff for their service.

"This is a speech I never expected to give," Boehner said. He was in tears later as Cantor addressed his 232 Republican colleagues.

Cantor's decision to leave his leadership post after losing last Tuesday to economist Dave Brat came on a day that Republicans began scrambling to build support and fill the leadership vacuum.

In addition to stepping down as majority leader, Cantor told colleagues Wednesday that he will not run as a write-in candidate in November.

Cantor's meteoric rise made him the pride of politically conservative Jews.

After a career in the Virginia legislature, he was elected to the House in 2000 and was made chief deputy whip just two years later, before his 40th birthday.

A prodigious fundraiser, Cantor joined with two other young Republican conservatives, Reps. Paul Ryan of Wisconsin and Kevin McCarthy of California, ahead of the 2010 elections and formed the Young Guns political action committee, backing young challengers to a party establishment seen as soft in the wake of Barack Obama's 2008 presidential win.

Cantor at first embraced the Tea Party wave, and carefully hewed to the right of the House speaker, Rep. John Boehner (R-Ohio), whom he reportedly hoped to challenge.

Cantor, who barely contained his dislike for Obama, was a lead player in forcing Boehner to shut down government in 2013. The shutdown was seen as disastrous for Republicans, and more recently Cantor began to steer center, notably in advancing an interventionist foreign policy and embracing aspects of immigration reform.

Cantor has said that his own background, as the grandchild of Jewish immigrants from Eastern Europe, informed some of his views.

Since 2009 he has been the only Republican Jewish member of Congress. He has delved into Jewish learning as he ascended to his party's leadership, taking private lessons with rabbis.

Washington Post reporters Paul Kane, Chris Cillizza, Robert Costa and Ed O'Keefe contributed to this article.