The answer, not entirely unsurprisingly for students of party politics, has a lot to do with the election of Barack Obama. Michael Heaney and Fabio Rojas have a “nice article”:http://www-personal.umich.edu/~mheaney/Partisan_Dynamics_of_Contention.pdf (warning – not very well scanned PDF), that looks at changes in attitudes among anti-war protesters over time (they and their colleagues undertook repeated spot surveys at anti-war demonstrations). As the perceived threat of Bush’s presidency receded, Democratic partisans began to reinterpret policies through a partisan lens, and the underlying coalition between pro-Democratic organizations such as MoveOn and the anti-war movement broke down, Democrats withdrew from the anti-war movement. The graph below (taken from Fabio’s “post”:http://orgtheory.wordpress.com/2011/03/29/democrats-killed-the-antiwar-movement/ at OrgTheory) illustrates this nicely. Interestingly, however
bq. The withdrawal of Democrats does not account entirely for anti-Obama views within the movement, evidenced by the negative, statisticallly significant coefficient on the time component of the attitude-formation equation, even after controlling for the changing partisan composition of activists. Thus, while Obama initially had an ally in the movement after his nomination for the presidency, the alliance had largely – if not entirely – vanished by the end of 2009.
