Not personally, but through his newspaper...
From Dean Baker at the Center for Economic Policy and Research (on October 1, 2015) who writes:
"The Washington Post's difficulties in separating its news and opinion pages showed up again in a piece by David Fahrenthold that warned the public against Senator Bernie Sander's agenda in his presidential campaign" [and concludes] "Anyhow, we get it. The Washington Post really does not like Bernie Sanders and is willing to ignore standards of journalistic integrity to try to undermine his campaign. We'll see how they do."
Jeff Bezos (founder and CEO of Amazon.com) purchased The Washington Post earlier year. His personal wealth is estimated to be $47 billion, ranking him 4th on the Forbes 400 list of multi-billionaires.
The super-rich "libertarian" will be influencing the "mainstream" media just as the "conservative" Rupert Murdoch does with Fox News (etc). We have 6 corporations that control 90% of the media — influencing public opinion, politics and government policy.
Reason is an American libertarian monthly magazine published by the Reason Foundation. Jeff Bezos, who was named one of Reason's "35 Heroes of Freedom" in 2003, has contributed money in the past to the Reason Foundation, a 501(c)3 nonprofit that publishes the website: www.reason.com
Senator Bernie Sanders (a self-described "democratic socialist") caucuses with the Democrats as a "progressive" (FYI: FDR was a progressive). So it should be no surprise that the anti-government Bezos would use dirty tactics to discredit Sanders, who believes in "better" government.
The Washington Post has gone after Social Security and other issues that "libertarians" and "conservatives" and Republicans have always been strongly against: programs that benefit the 99%.