The Democrats could not speak up then nor can they speak up now because:
1) GWB bullied them. The country was still reeling from the 9/11 attack and wanted revenge. Speaking up against the war would’ve been ridiculed as speaking up for the enemy.
2) Saying that they changed their minds now would be ridiculed as flip-flopping. The political environment is now such that politicians will try to stay steadfast in order to secure their political future. The reality of life, however, is that you need to apply different solutions to different problems at different times; or perhaps different solutions to the same problems. For that reason, I like the know unknowns lecture by Rumsfeld.
Unfortunately, the public associates “moral clarity” with holding on to your initial position.
This is unfortunate for Bush also because it limits his options on Iraq. He talked so much about the beacon of democracy and prosperity that Iraq would become that anything short of that will be considered a failure.
The Republicans started down the path of black and white, and good vs. evil. Now they have to live with the political environment they created.
I admit, the times leading up to the war all through Mission Accomplished were tough for me. There were very few people I knew (except for my European friends) who shared the belief that the war was a mistake. If you don’t think it’s tough, think of the times in 2003 when every one was “investing” in 2nd and 3rd homes and you were scratching your head wondering how to make it all financially add up.