The Southern Baptist Convention is the system that loosely connects the churches. For years, it was pretty much what is sounds like—an annual get together where members from the various churches gave speeches, ate traditional convention rubber chicken, and talked about the focus of the church over the coming year. For decades, most churches looked on this convention as a huge bore, and finding someone willing to attend usually required fingering a deacon who wasn’t quick enough to come up with an excuse.

But starting in the late 1970s, a group of extreme conservatives within the church got a simple idea. They encouraged their members to volunteer for the convention, and they reached out to like-minded members of other churches to persuade them to come. As soon as they held a majority at the convention, they demonstrated what so many members in all those churches had forgotten: The convention held incredible power. Using that power, they redefined what it meant to be a member church, requiring that each church swear to follow a very strict set of teaching, including things like biblical inerrancy and conservative social positions. At all levels, from pulpits, to seminaries, to missionaries, progressives and moderates were expelled.

Almost 2,000 churches left the convention. The conservatives didn’t care. That only helped them to purify their revised organization; in the wake of those departures they grew stronger by incorporating the idea of “mega-churches” that recreated many of the institutions, like youth sports leagues, that had once been part of the community. The SBC emerged from this takeover apparently weakened, but ultimately grew to be a powerhouse in the conservative movement and a cornerstone of the modern Republican Party. Whenever you see the term “evangelicals,” you can think of it as “Southern Baptists and others,” because the SBC is now the largest organization on the “Christian Right” by far—over 47,000 churches and 14 million members.

The reason for recounting this history is that something very similar has happened with Republican organizations at the state and local level.