The 2014 election cycle probably represents Mr. McConnell’s last chance to regain the title of majority leader, and he seems determined not to let conservative activists spoil his chances. His actions and comments both publicly and privately since the shutdown have shown that he does not intend to brook much interference from conservative activists.

Just as important, Mr. McConnell does not want to regain the majority only to find himself surrounded by conservative firebrands like Representative Steve Stockman of Texas, who is now challenging Senator John Cornyn, the No. 2 Senate Republican. Mr. Boehner has proved that presiding over an ungovernable majority is not an enviable job.

Seeming to relish his new liberation, Mr. Boehner on Thursday skewered the organizations for a second straight day, just a few hours before the House overwhelmingly approved the budget plan at the center of the dispute with the support of 169 Republicans. Sixty-two opposed it.

“They’re pushing our members in places where they don’t want to be,” Mr. Boehner said. “And frankly, I just think that they’ve lost all credibility.”

Conservative leaders said they viewed Mr. Boehner’s attacks as tantamount to a declaration of war and accused him of trying to change the subject from a budget plan that increases spending and sacrifices earlier hard-won fiscal victories by House Republicans.

Dan Holler, the communications director for Heritage Action, said he found it particularly remarkable that one of the biggest fund-raisers in Washington would suggest that a group was doing something to generate contributions.

“This is absurd,” Mr. Holler said. “Only in Washington could you have guys who go to PAC fund-raisers at swanky restaurants accuse outside groups of doing something for fund-raising. It is one of those petty attacks that is intended to shift the conversation away from the policy.”