On Monday, Bernie Sanders attacked the Washington Post.
He said the Post is "not one of my great supporters" due to the fact it is owned by Amazon CEO Jeff Bezos.
Sanders has frequently attacked Bezos and Amazon for the treatment of the company's workers.
Sanders pressured it to introduce a minimum wage of $15 an hour — which it did in November last year.
The Washington Post's executive editor Marty Baron called Sanders' comments a "conspiracy theory."
Journalists compared Sanders' comments to Donald Trump's anti-media rhetoric.