The key difference to the left between Iraq II and WWII is that in WWII we eventually ended up on the same side as their favorite country the USSR. That made FDR immune from such protests. I say eventually ended up because in the Lend-Lease days it was the UK with support from the US holding out against Germany with support from the USSR.
You would be stunned with how many professors on college campus today border on nazi sympathising with condemnations on the US regarding WW 2.
I had a professor years ago who thought that Truman should be considered a war criminal for dropping the atomic bombs on Japan.
On the O'Reilly factor running up to the afghan war, a student activist argued that ww 2 could not be morally justified for any cause.
Several left wing groups also today morally condemn the US at that time as being no better then the Nazi's of that era, and Noam Chomsky has argued the same thing himself.
On some liberal websites, I've lurked and seen some argue that was the nazi's did to the jews was there own business, and the US (being the imperialists we are) had no right to war with germany which did not attack us.
The writer of this article is sadly assuming more common sense from the left then they actually have.