Observe how Democratic participation sharply drops after the Obama inauguration.

My collaborator, Michael Heaney, and I have a new working paper called “The Partisan Dynamics of Contention: Demobilization of the Antiwar Movement in the United States, 2007-2009.” The key argument is that the decline of the antiwar movement can be attributed, in part, to the fact that Democrats have stopped using the peace movement as a platform for anti-Bush sentiment. In other words, at its peak, the ranks of the antiwar movement were swelled by partisans. Once Obama won the presidency, and other issues emerged, the movement shrank when Democrats stopped showing up. The remaining protesters were more likely to be non-partisan or third party, and these non-Democrats were more likely to disapprove of Obama’s management of Iraq and Afghanistan. When Democrats gained power, the movement converged on a core of peace activists who were not strongly identified with the Democratic party.