I can site specific examples to back up my claim. Gay marriage is the most recent issue to come to mind. It wasn't all that long ago that even democrats from red states opposed it as anti-family. Now republicans from red states support it. That didn't happen via big corporations making campaign contributions. That happened because politicians realized the growing popular support for gay marriage necessitated them reversing their positions or facing being voted out of office.
Blind cynicism isn't cute.