To begin, the United States Speaker of the House is elected in a vote by the entire House of Representatives. Traditionally, the majority party meets on its own to select a candidate. As long as everyone falls in line behind that candidate, the majority party can elect that candidate regardless of what the minority wants.
The system, however, falls apart if “not enough people” in the majority party back the party’s candidate. Moreover, we can quantify what “not enough people” actually equals: the key here is the number of seats over and above the bare minimum needed to win a majority vote. In the US House of Representatives, that number is 218 (435/2 = 217.5). If a party holds the majority by a single seat — 218 vs. 217 — then essentially every single member of the majority party could, in theory, threaten to defect to the minority party and defeat the nominee of the majority party.
Currently, the House is made up of 247 Republicans and 188 Democrats. This makes the magic number 30: if 30 Republicans were to join with the Democrats to vote for Nancy Pelosi then — provided the Democrats’ caucus held — Pelosi would be elected Speaker of the House. As we have heard repeatedly today, there is a group of conservative House members known as the Freedom Caucus, numbering somewhere around 30-40 members, opposed to McCarthy. Due to the size of the Republican majority, this is a large enough group to deny the party a majority on the floor of the House.
Media coverage today has focused on the question of which Republican candidate is likely to replace McCarthy, with Paul Ryan receiving the most intense speculation at the current moment. However, should 30 Republicans want to defect to Pelosi, she could be elected speaker tomorrow.
Would the Freedom Caucus give Pelosi back the speaker’s chair? Seems pretty unlikely, although stranger things have happened in parliamentary democracies that routinely require coalition governments to rule. Occasionally governments are formed that contain both far-left and far-right parties. Slovakia had one of these in the 1990s, and the current Greek government has this flavor as well. Still, hard to imagine this happening in the US, although the strategic implications vis a vis both the 2016 elections and the internal power struggle in the Republican party are sort of fun to consider.
Of course, it is equally possible — at least from a mathematical standpoint — that the 30 most liberal members of the Republican caucus could join with the Democrats to back a Pelosi speakership. If we are going to go into this fantasy world, then one could imagine a coalition of Republican legislators from swing districts in traditionally blue states rising up to put the needs of the American people (e.g., not defaulting on U.S. government debt) ahead of fringe elements determined to hijack the political process for their own political goals, etc. Again, hard to imagine this happening here.
This type of scenario, however, is not entirely unimaginable in the United States. To do so, however, we have to transport ourselves to a far-away time in New York state politics — 2009 to be exact — before the most recent indictments of the majority leaders of both legislative houses (although not long after our governor had resigned in a prostitution scandal). The N.Y. state Senate has 62 members, and in 2008 the Democrats captured control of the chamber — for the first time in decades — with a 32-30 majority. This made the magic number effectively 2, and, lo and behold, in June of 2009 two Democrats did indeed join the Republican caucus and elect Republican Dean Skelos as majority leader of the New York state Senate. This being New York state, Skelos would go on to be indicted on extortion charges, but nevertheless, the example is out there. Even in the United States, these things can happen.
So let the games begin!