Buttigieg’s implication was that while O’Rourke’s “war” against Christians might be justified, there’s also a chance that those efforts might ensnare a favored progressive group. This isn’t a defense of religious tolerance as much as a warning — a good one — that any state empowered to target problematic Catholics or Evangelicals could one day come after Unitarians or Reform Jews, as well.
The interaction allowed the media to frame Buttigieg as a moderate on issues of church and state. Something he most certainly is not — except in relation to O’Rourke, who, as others have noted, is the id of the Democratic party. All told, O’Rourke’s real sin wasn’t the positions he took, but his abandonment of incrementalism. At root, the fundamental ideas that propelled Beto aren’t very different from those that are propelling Buttigieg, whose defense of the Constitution is contingent on progressive outcomes and the current state of identity politics, rather than on neutral principle.