You can rejoin the UP? I thought once you left you were out for good.
Anyway, I don't dislike the potential for limiting starbases in general though. It does add a different spin on the game, and I suppose I can deal with that.
Still, I wonder if the AI understands the ramifications of passing it. Using it to keep me from going for an influence victory by spamming influence bases across the galaxy makes good strategic sense. It also makes sense to enact it if I'm working on laying down a military base backbone throughout their empires

. However, using it to rein me in once I already have a large starbase network in place seems foolish to me. Sure I can't pump out even more bases now, but unless the other civs have equally big networks established they've lost a lot more potential economic and military power than I have. The only thing they accomplish is freezing the status quo . . . a move not likely to be to their benefit when they're lagging behind.
Anyway, the point of my rambling is that although the law is phrased in a way that suggests it favors the weaker races, depending on the circumstances it might actually take away one of their better chances of making a comeback (like mass producing econ bases to try to build up a competitive industry or defending their turf from superior invaders using military bases).
Admittedly I haven't really paid attention to how the AI votes on this particular law . . . I'm usually too busy cursing and switching production from constructors to my nastiest warships. If they don't want my shopping malls maybe they'll be happier sucking on the business end of my disrupter beams?