I'm not so sanguine about that, Hildy, after seeing this year's list: Brokeback Mountain, Capote, Crash, Good Night and Good Luck, Munich. If the film's grinding a liberal axe, the Academy seems to swoon over it. (Public acclaim is nowhere on the Academy radar, either; those 5 nominees together grossed less than The Chronicles of Narnia.)
There's a difference...all the movies you mentioned, although liberal leaning, were very good movies in the way movies should be...entertaining, beautifully acted, directed and photographed. You might not like the content, but you can't dispute the quality of the movie. Davinci Code is, apparently, just not a good movie. The only one on your list that I think I would agree somewhat is MUNICH, because it didn't get great reviews and, ironic enough, the reviews were alot like this one, boring, long, etc. But you can't discount the Spielberg factor. The Academy has never been unusually kind to Ron Howard, so I doubt it will get any major nominations...maybe some technical ones.