The recent discussion of the 27A issue with no-intervening-election pay reductions reminds me of an idea that occurred to me when the issue of no-intervening-election pay increases in Louisiana came up a few years ago. If "privileges or immunities of citizens of the United States" in the 14A just means "privileges given in the Constitution," which some suggest it does (e.g., Allen Thurman, Hugo Black, and Kurt Lash--for citations see here), would a state pay increase given to legislators without an intervening election violate the Privileges or Immunities Clause? For my part, I disagree with that definition, and don't think the consequence is sufficiently absurd to be a good reductio ad absurdum, but I'm still curious. One issue, which shows up in the (far more important) Establishment Clause incorporation context, is whether the 27A is structural, as opposed to privilege-recognizing or privilege-granting. There might be differences between no-intervening-election increases and reductions on that score: the taxpayer-protective ban on increases might be a constitutional right, but not the ban on reductions.