NY, CA will take minimally 1 to 1.5 generations. Especially CA, it is completely gone.
Since the CA GOP is the beating heart of RINO-dom and completely happy to keep the scraps they now have, it is going to be hard to put together a coherent ground game to start undermining Leftist groupthink there. Trump might be able to do it, but I think it will take more time - and ultimately more of a Ron Paul-like figure to appeal to them. Find a libertarian-talking, good-looking, 45-ish, Hollywood actor to run as a Republican and he could easily sweep the state - especially if he is Hispanic.
What percentage of CA Blue votes are deportable? Trump can make it closer. He can also stop the rest of the country from funding, federally, some of the nonsense that attracts the non-deportable ones there. The half-life of fully self-funded liberalism is short.
If we had to show valid citizenship ID, CA would be redder.