The DNC has filed a civil lawsuit against members of Trump's campaign party, Russia, and Wikileaks. On the surface, it seems almost petty and insignificant, but it's actually kind of brilliant and far from what I usually expect from the Democratic party.
If people like Manafort, Kushner, and Trump Jr. have to testify under oath on a civil witness stand, Congress can't protect them with closed-door sessions. Every detail will be right in front of the media. Plus, the suit already has presented previously undisclosed information, such as the exact dates of the data breaches.
This is a tactic the Dems used against Nixon as well. The suit was settled on the day Nixon left office.