It isn't that hard to keep people organized and energized for politics all the time, to make it seem important and to make them think that they can contribute in some small way. And, no, clicktivism doesn't count. Victory (Obama) brings complacency generally, but the people with all the money and influence are rarely interested in that kind of organizing. And even grassroots require leadership and, yes, money.
If not getting out on the streets, then what? There were a lot of quirky quixotic efforts during the Bush years. They mostly faded away or got absorbed into the borg.
Political parties are membership organizations. They should ask something of their members other than "CONTRIBUTE OR DIE!!!!"