“You got elected because you weren’t Obama,” said Anthony Sykes, a conservative state senator, speaking of some of his hard-line colleagues. “But the Obama well went dry. And you’ve got to produce some results now.”

That a purge of hard-right lawmakers had even been considered is a function of the scale of Republican domination in Oklahoma. Long a minority party operating chiefly out of the Chambers of Commerce and Rotary Clubs of Tulsa and Oklahoma City, Republicans went on a partisan land rush over the past couple of decades, winning rural and small town seats that had been in Democratic hands since statehood.

“When I got elected it was kind of a fluke,” said Mr. Faught, who in 2006 won a seat in Muskogee that had never been held by a Republican.

With ever-expanding majorities, longtime Republicans saw a chance to pass long-delayed priorities like tort reform, but the arrivals from the party’s new frontiers came with their own ideas. Lawmakers barely known by the party leaders were now in the headlines for forming a legislative caucus to stamp out the Muslim Brotherhood in Oklahoma or proposing to screen thousands of students for possible deportation.

This was messy but manageable in the good times. Then the fiscal emergency hit. Party leaders knew they had to come up with a plan, but a vote to raise taxes, already extremely difficult in Oklahoma, was proving next to impossible, even with a supermajority. In March, the House finally, and barely, managed to pass a tax package to pay for teacher raises. Nineteen Republicans voted against it.

“You had the governing Republicans versus what I call the ‘Let’s barely keep the doors open’ Republicans,” said Chad Alexander, a former chairman of the state Republican Party. “And the Democrats.”

Of those 19 ‘no’ votes on the tax package, only four are left running in the general election. The rest either ran into term limits, chose not to run or lost in primaries, defeated by fired-up teachers and the dark-money-fueled housecleaning of the Project.