So my question would be, regarding the poll........what were the ages of the people polled? I think that could be a big factor for people to determine if the war was justified or not. What does a 30 yo person, in today's world, know about WW II? Do they know that yesterday was the anniversary of D-Day? Likely not. If you're in college now, it's unlikely you discussed anything remotely about WW II in your high school history class. On D-day alone, approximately 4500 Allied troops were killed. If that were to take place now, people would be devastated. Not that losing 4500 people at that time wasn't a bad thing, but it's all a matter of context.
You could argue our involvement in Europe and the invasion into France on D-Day was questionable, as Nazi Germany had YET to directly impact us. Hitler was a horrible dictator, and the rate he was going, he would have held most of Europe.
After helping defeat Nazi Germany, Patton wanted to continue on into Eastern Europe to neutralize the Russians, but he had been taken out of command.
Our involvement in the Pacific.....Japan attacked us, right? I would argue, too, a totally different generation of Americans. That's why I ask what the age of the people were who were polled. Those wars were "way off" in Europe, Africa and the South Pacific. You only knew of what happened by newspaper or radio. Now, it's in our homes and on our personal device(s).