I think what you have to remember is that timing is important. The citizens of the United States didn't want to get involved in WWII before Japan attacked. As a nation, Japan was easy to blame. Today we once again have a significant portion of the populace that not only doesn't want to get involved, they actually want to aid the enemy if they can. Today we have what some belive to be rogue agents committing the "Pearl Harbor" envents. It's much harder to focus, especially when our leaders get up and swoon over the good Moslem people.
That is the reality we have to deal with.
The left are idiots no doubt. I'm still not convinced they wouldn't support U.S. action if a nuke were to go off on U.S. soil. Still, that's about a 50/50 from where I sit.