Mike Johnson Becomes the Speaker of the Whole House. For Now.

The notion that the speaker serves the whole House is often tossed around, but rarely the case.

While the position is established in the Constitution and under longstanding House rules entails presiding over the entire institution, the speaker has historically played a highly political role, installed by the majority party to ruthlessly execute its will and legislative agenda. But circumstances have changed.

Representative Mike Johnson can now, for better or worse, truly lay claim to being speaker of the whole House, after Democrats saved him from a Republican-led coup on Wednesday in another remarkable moment in a chaotic Congress filled with them. Had Democrats not come to his rescue, the votes existed in his own party to potentially oust him.

It was the logical outcome of a session in which House Democrats, despite being in the minority, have repeatedly supplied the votes and even the procedural backing to do most of the heavy legislative lifting to stave off default, fund the government and aid U.S. allies, forming an uneasy coalition government with more mainstream Republicans.

The result left Mr. Johnson, a Louisiana Republican still new to the job, indebted to Democrats even as he immediately sought to distance himself from them by emphasizing his deep conservative credentials. Democrats said their support for him underscored their bona fides as the grown-up party willing to go so far as to back a conservative Republican speaker to prevent the House from again going off the rails.

Now the two parties will have to navigate this previously unexplored terrain as they head into an election season that will determine who is speaker next year.

The reality is that after passing the foreign aid package including funding for