Not necessarily Google. Non-Google President Obama supporters are the more likely culprit. If enough people label the website as spam on anti-spam websites or through anti-spam programs, the website will be blocked by anti-spam programs, etc. Or the website might really have a ton of spam advertisements. Or it could be somebody at Google.
Yep, could be the handiwork of Netroots. They are famous for such nonsense.
Totally unscrupulous.