U.S. Rep. Silvestre Reyes, D-Texas, will have to give up his seat in the House of Representatives after losing the primary in his state, thus ending a 16-year-political career in Washington.

Reyes lost his seat on Tuesday in Texas District 16, a district with a high proportion of Hispanics and Democratic leanings that he has represented for eight terms. Beating him in the primary was his Democratic rival, former El Paso councilman Beto O'Rourke.

The final vote count showed that O'Rourke beat Reyes - who is of Mexican origin - by 23,248 votes to 20,427, or 50.5 percent to 44.4 percent, a situation that avoids the need for a runoff election.

Reyes, the former chairman of the House Intelligence Committee, had been supported by top Democrats and the party's political machinery, including President Barack Obama and former President Bill Clinton, the latter of whom even participated actively in his reelection campaign.

The unexpected defeat for Reyes, who strongly pushed the issue of border security and immigration reform in Congress, was due in part to the enormous infusion of money by the "Campaign for Primary Accountability," a "Super PAC" that launched a campaign to unseat him.

That group, which spent around $361,000 in advertising and attack ads, also tried without success to ensure the defeat of Republican Ralph Hall, who was vying for another House seat in Texas with a rival from that party.

A spokesman for the group, Curtis Ellis, said Tuesday night in a communique that O'Rourke won because of heavy citizen participation despite the fact that Reyes had the backing of the Democratic hierarchy.

After a campaign that analysts described as a fight between "experience and new blood," Reyes blamed his defeat not only on the activities of the Super PAC but also on his rival who, he said, ran a "filthy, dirty campaign."

Reyes, who based his own campaign on his vast experience in Washington and attacked O'Rourke for supporting the legalization of marijuana, said that his team ran a wide-ranging, "professional campaign" with the voters of the district.

The Campaign for Primary Accountability, which favors term limits on political officeholders, already had managed to unseat Illinois Republican lawmaker Adam Kinzinger and it contributed to the defeat of Ohio Republican legislator Jean Schmidt.

The group has made clear that its next target will be Democratic New York Congressman Charles Rangel.

The Super PACs, groups created as a result of several rulings in 2010, individuals, unions and companies may make unlimited contributions to political campaigns and their funds may be spent to help ensure the victory or defeat of a federal candidate.

Although by law Super PACs cannot directly coordinate their activities with a candidate, in practice they wind up being an extension of the campaign, activists claim.

O'Rourke on Tuesday night told a local Texas media outlet that his victory came about because he ran "a great campaign" and now he has his sights set on measures to improve the community.

O'Rourke will vie for the seat with Republican Barbara Carrasco in the Nov. 6 election and, because the district is mainly Democratic and Hispanic, analysts predict that he will obtain an easy victory. EFE