Also, if you're referring to his previous belief that we need a healthy Democrat and Republican party, I'll point out I've said the exact same thing here more than once.
Unfortunately, the Democrat Party isn't healthy anymore, at all. It's dangerous and radical in every conceivable way, and that's a shame.
When Reiner spouted that view, he was just another typical misguided leftist like the hordes of them out there, but at least reasonably sane back then. Just as the Democrat Party has completely lost its mind, so did Rob Reiner.
As I've already said, it's sad to waste your last years on earth stewing in that much hate and bitterness.