Seems obvious that Google wouldn’t purposefully introduce political bias into search results. But since they rely on content from many sources there is always room for leanings to creep in that reflect society and media at large. The debate on search bias is important and I’m glad people are having it.
Barry Schwartz points to this Hacker News Thread in which Ryan Moulton, a Google employee who works on ranking says:
I work at Google on ranking algorithms for Search. I’m aware of everything that controls how web pages are ranked. If I ever encountered a system that was designed to alter the results for political reasons, I would resign.