I think his politics are repugnant, but less than 1% of Google search queries for his name are looking for Dan Savage's prank. Google knows this. Google obsessively tweaks all manner of other links in the index. But Google's overall politics happen to be the same as my politics, so Santorum gets unequal access to the 2012 Internet.
Savage's prank actually discredits the Internet. Surely nobody's mind is going to be changed by that disgusting link. Instead, it just serves to associate Internet content with the culture wars. I don't think I'll upset too many HN'ers when I assert that the people most likely to be offended by that link are the people we'd most like finding better ways of informing themselves than talk radio.
Finally, and most obviously, we all happen to share the same sense of humor and political stance as today's Internet gatekeeper. But we are by no means assured of compatibility with the next one.
That "Santorum" link is perhaps the most notorious attempt ever to game Google's search rankings. Google should penalize the shit out of it.