Beto O’Rourke, who is well known for questioning the policy of drug prohibition, defeated eight-term congressman Silvestre Reyes, former chairman of the House Intelligence Committee, in a Texas congressional primary yesterday. In the heavily Democratic, 78 percent Hispanic El Paso district, O’Rourke is almost certain to win in November.

President Obama endorsed Reyes, and former president Bill Clinton campaigned for him. The Washington Post notes:

Reyes made an issue out of O’Rourke’s support for marijuana legalization, which the congressman opposes. In one Reyes ad, a group of children say “no” to drugs while “Beto O’Rourke wants to legalize drugs” flashed across the screen.

O’Rourke campaigned as a “true Democrat” on economic issues. But in addition to his criticisms of the drug war, he endorsed term limits and criticized Reyes for supporting the Patriot Act.

Last November, O’Rourke spoke at Cato’s conference “Ending the Global War on Drugs,” along with the former president of Brazil, the former foreign minister of Mexico, and other world leaders. Watch the video:

O’Rourke was also interviewed for a Cato podcast. Back in 2009, Cato’s Juan Carlos Hidalgo participated with O’Rourke in a conference on the drug war in El Paso.

Reyes is the sixth congressional incumbent defeated in a 2012 primary, which doesn’t sound like a lot. But the Campaign for Primary Accountability, which supported O’Rourke, notes that the average number of incumbents defeated in any primary season is three.