This Democratic senator was ridiculed for citing Russia's threat to his state's elections. Mueller's report actually bolsters his claim.

Mother Jones reporter Pema Levy points out that one key line in Robert Mueller's findings buttresses former Democratic Sen. Bill Nelson's assertion last year that Russian military hackers had compromised Florida's election systems:

We understand the FBI believes that this operation enabled the GRU to gain access to the network of at least one Florida county government.

At the time, Nelson, who was up for re-election, was bitterly derided for his warning, which he said was based on classified information. As Levy puts it, "Republicans and the media alike painted his comments as dangerous make-believe."

That even included the Washington Post's "fact checker" awarding four "Pinnochios" to Nelson, insisting, "Not a single speck of evidence backs him up, and we have serious doubts whether the classified information he cited even exists." But even if the press were to walk this back now, reporters carried water for the GOP by undermining the credibility of anyone who might sound a similar alarm in the future.

And while we don't know whether Putin's hackers were able to manipulate the election, it's important to remember just how close Nelson's election was: He lost to Republican Rick Scott by just 10,000 votes out of 8.2 million cast statewide—a margin of only 0.1 percent.