In a democracy public perception of reality directly correlates to your ability to perform as a politician.
The Bush administration used the full thrust of the office to knowingly foster false perception of reality in huge swaths of the population. Rendering objections moot.
The ultimate blame lays with the deceiver. Even though representatives of all parties votes for the invasion, they acted in a reality manufactured by lies and they represented the will of their supposed voters.
You may accuse them as spineless, but there's still magnitude difference between deceiving the public, and failing to convince the public it's all lies.
Losing this distinction just makes the crooks stronger.
What is the proof that one party did it against the will of the people, while the other went with the will of the people? Given how much ongoing violence was continued and expanded even once the democrats has a president and congressional majority, it seems like both parties were and are happy to perpetuate imperialist violence in the name of a fictional protection.
