Hillary Clinton went on the Late Show Tuesday night to talk about her book What Happened and, well, what happened; that is, why she lost the 2016 election.

"It was very painful and difficult, but at the end I really feel like I've done my very best to lay out what happened so that it doesn't happen again," she told Stephen Colbert about the book. "That's my primary goal here, so that it doesn't happen again."

So how does Clinton think Democrats can keep from losing another winnable election? By stopping Russian meddling. Clinton told Colbert that she believes the Russian fake news propaganda campaign succeeded in influencing public sentiment against her, and it will happen again.

"I'm a bit of a Paula Revere, trying to sound the alarm about this," she said of Russian president Vladimir Putin. "You gotta understand what Putin's strategy is. He really doesn't like democracy. He thinks it's an inconvenient, messy process. And he doesn't like us. And he wants to destabilize our country, sow doubt about our democracy," which he did with Facebook ads.

"He wants to undermine how we see each other, how we respect each other, how we support our institutions and our society," she said. "I think that they believe they had a good outing in 2016, and I think that they will be back in 2018 and 2020 unless we stop them."

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