(a) Google believes that most of its users really are looking for Dan Savage's prank when they search for the name of one of the best-known national Republican figures of the last 30 years.
(b) Google is deliberately choosing not to adjust this particular search result for reasons of ideology or pragmatism.
Please understand that I could give a rats about Rick Santorum. I find him odious. I firmly hope he does win the GOP nom so that Obama can win 2012 in a walk.
But [santorum] does not return that particular SERP because the word "Santorum" organically became associated with that particular idea. A group of people decided to rewire, well I guess the Internet, to force that association. If they can do it, anyone else can too. Google's search results should be more credible than that.