This being my second semester at a community college, I have not had any trouble incorporating my personal views into my papers as far as it affecting my grades. However, several of my friends have told me that once I transfer to a university, professors can ultimately fail students for conflicting views (political, religious etc.). Is there any truth to this rumor?
Yes, my views typically conflict with professors'. No, I can't elaborate.
As others have noted, a professor can't (in theory) fail you because you have views that conflict with their own.
In all my years of schooling, I don't think I've ever had a professor fail me because of my views (or, rather, never had a professor lower my grades because of my views). And I've had a lot of schooling so far. That being said, I've definitely had a few professors who I subjectively felt didn't like me / my views and did grade things a little tougher. No way to prove things like that, usually, as grading in many disciplines can be rather subjective.
The one major issue with your professor's quote is that the U.S. did not (likely) know about the concentration camps until troops arrived at said camps. The U.S. did know of Germany / Japan's imperialistic motivations via the Blitz against Poland and other countries, etc, and the attack on Pearl Harbor basically forced the U.S. to enter the war.
As for the whole issue of agreeing / not agreeing with a professor: The good professors will be happy to debate with you, but if you don't have a (well) reasoned argument in your favor, they will likely make mincemeat out of your views. The bad professors, of which I've never had any, will likely not be able to act in such a professional manner. In that case I'd recommend simply keeping your head down and not getting into it with them, unless it is an egregious issue. They will only likely be affecting your grades for a semester or two.
Oh, and professors
do talk about students with whom they've had trouble with. So don't go making any unnecessary enemies.