A small group of conservative leaders had gathered in the Trump International Hotel last week for a friendly discussion about the year that was ending and their priorities for the year to come, when Stephen K. Bannon spoke up.

“I’m not going to name names,” he snapped, looking around the room as he complained about being left virtually alone to defend Roy S. Moore, accused of sexually molesting and assaulting teenage girls, while the Republican leadership and Democrats bludgeoned the Alabama Senate candidate. “If we want to win,” he added, according to three people who were in the room, “We need to stop playing footsie with the establishment. They’re just going to string you along, pat you on your head, and send you on your way.”

Mr. Moore’s loss — which will send the first Democrat from Alabama to the Senate in 25 years and cut the Republicans’ already thin majority to a single seat — has only stoked Mr. Bannon’s discontent and stirred up fresh worry that the party is again descending into Tea Party-type spasms of self-defeating rage.

To avoid that, many Washington Republicans have no intention of patting Mr. Bannon on the head. They intend to kneecap him before he has the chance to recover.

“First is to dry up his money,” said Scott W. Reed, the chief political strategist for the U.S. Chamber of Commerce, a pillar of the Republican establishment, explaining how top Republicans in Washington were making a new round of calls to donors across the country to press them not to donate to Mr. Bannon or the candidates he supports.