From the July 16 Senate Judiciary subcommittee hearing on “Google and Censorship through Search Engines” :
SEN. MAZIE HIRONO (D-HI): I repeat now what I said then. Claims of anti-conservative bias in the tech industry are baseless. Study after study has debunked suggestions of political bias on the part of Facebook, Google, and Twitter.
In April, Media Matters completed a 37-week study into alleged conservative censorship on Facebook. It found that right-leaning pages actually outperformed -- outperformed -- left-leaning pages in terms of overall interactions with users.