The non-CATXOKLA swing states can merge with each other and a few red and blue states to form an even bigger bloc :)
I think there’s a range of stable equilibria here, depending on the sequence of merges, with the largest bloc being a majority of any size. I think they all disenfranchise someone, though.
So you can’t ever get to a national popular vote, without relying on things like the NPVIC which shortsightedly miss the obvious dominating strategy of a 51% attack against American democracy.
It stops being in the interests of CATXOKLA to invite more states once they’re already big enough to dominate national electoral politics.