With Republicans embroiled in an influence-peddling scandal that could threaten their control of Congress, the biggest pressure for reform is coming from lawmakers who charge that the party’s woes have come from abandoning its core conservative principles.

Jeff Flake, an Arizona Republican congressman who co-led the petition drive that helped oust Tom DeLay, the House majority leader, said in an interview yesterday: “We don’t just need a new majority leader, we need a course correction.