The DNC is the only reason you're not currently enjoying a second-term Sanders and a sane Supreme Court.

There's nothing to comprehend. They don't understand how things work. And can't commit for any length of time. They want change. But Democrats having to fix Republican damage struggle to do much else. So they figure that they will vote for the opposition. But the opposition always makes things worse. So they vote for Democrats to fix and change things. Democrats start to fix things but they don't do it fast enough so they vote for the opposition. In the opposition makes things worse so they vote for Democrats to fix it and change things. The Democrats fix things as much as they can but they can't change anything so they vote for the opposition etc etc etc.