Lol, the Democrats aren't very good at chess. The Republicans won control of the House in 2010, and the Democrats spent the next six years emasculating the House and shifting all of the power of government into the Senate and the legislative and judicial branches.
Meanwhile, as the Democrats were securing a tiny majority in the House, the Republicans were picking five new seats in the Senate (something that hasn't happened in nearly half a century), Trump gets at least three Supreme Court picks, and Trump has already appointed 65 federal judges just in his first two years in office.
The Democrats lost. And I mean they lost, period. Not just the election - they lost the entire political game. It's over. They may become a viable political party at some point in the distant future, but right now, they are out of the game altogether.