Dade Phelan may soon have the distinction of becoming the first Texas House Speaker to lose his seat since 1972, when Democrat Fred Head, one of those rare do-gooder types in state government, knocked off Rayford Price. Phelan’s opponent, oil and gas consultant David Covey, is no Fred Head, and little about this matchup has to do with good government. Still, Phelan’s inability to avoid a runoff against his Republican primary challenger is a political earthquake. Even if he does win his runoff on May 28 and clings to his Beaumont district, his speakership is in jeopardy. The stench of defeat hangs over the two-term Speaker.

The GOP primaries this year were remarkably ill-tempered and contentious. Governor Greg Abbott targeted sixteen House Republicans who voted against his school voucher plan, knocking out six and forcing four more into runoffs. Attorney General Ken Paxton endorsed 47 candidates, part of his fervent campaign to punish House Republicans who impeached him. No one bore the brunt of those efforts as much as the Speaker of the House. In all, nine House incumbents, all but one an ally of Phelan, lost on Tuesday. Eight more are headed to runoffs against challengers who accuse them—as conservative as they are—of apostasy against, variously, the Republican Party, God, the Constitution, and Paxton. Historically, legislative incumbents have had tough sledding in runoffs, losing 27 of 34 since 1996.

The upshot is that the House will lurch, once again, to the right, and the dream of removing the last vestiges of restraint, however modest, will be at hand. The great economist John Kenneth Galbraith argued that capitalism needs “countervailing power”—unions, civic organizations—to function properly. Otherwise, elite business interests grow into behemoths and prey upon the weak. The Texas GOP may soon lack any significant countervailing power: the Democratic Party is missing in action, unions are constrained, outside the fervent Republican grassroots most voters are apathetic, and the more-responsible voices within the GOP are on the retreat.