Back in the 80's, Neil got a severe beatdown by the Geffen/Wenner/LA music industry velvet mafia for embracing Reagan and delivering quotes like this one about AIDS:
"You go to a supermarket and see a f*ggot behind the f*ckin' cash register, you don't want him to handle your potatoes." -- from a 1980's Melody Maker interview
Ever since, Neil's been a good little boy and has toed the line nicely for his masters. They were pleased with his anti-Bush "Rocking In The Free World", and he's made sure his public pronouncements are the correct kind ever since. California ranches and toy trains are expensive, you know.
Maybe living in liberalism central, Marin County, also had something to do with it.