Obama more or less demobilized all the people who had volunteered for him / fought for him / against the republicans after he got in power. When obama was sworn in, quite a lot of people predicted a sea change in the American political system, since Obama was seen as the tidebringer of a new generation of motivated Democrats. The problem was that since he chose to not use his immense popularity for much, a lot of that energy that came from the financial crisis and the wars in Iraq & Afghanistan was just allowed to vanish/dissipate, including a lot of the vaguely related groups that had helped Obama get elected. For instance the ACORN org which mostly did voter registration in poor / minority neighbourhoods was defunded after a Project Veritas hit-job, since Obama understood politics as him having to work with the conservatives (in both parties) and those guys fucking hated him at every turn.