If we were in WW II today, the democratic party and our current president would be firmly on the side of Hitler, Tojo and Mussolini.
Impossible to imagine Hitler's response to a US President Barrack Hussein Obama.
Hitler already considered America a "mongrel nation," and did I not hear recently the President referred to himself with that word?
But in Hitler's mind, regardless of any later conversion to Christianity, since Obama was born of a Muslim father, he is Muslim, period, and so potentially highly admired by Hitler for antisemitic reasons.
That Obama could cotton to Hitler is also impossible to imagine.
By any reasonable standard, Obama is simply FDR Jr. and like his political "father," would naturally gravitate toward that other great International Socialist dictator, "Uncle Joe" Stalin.
With Stalin and Hitler still official allies in 1940, that would certainly be enough to keep a President Obama, like FDR, out of Europe's war.
Also consider: in 1940, the American people were nearly 100% sympathetic with the western allies and appalled by Hitler's successes and atrocities.
Americans hugely supported being the "Arsenal of Democracy," since it generally meant full US employment paid for by the Brits -- what could be sweeter after a decade of Great Depression?
But there were, as yet, no prominent political voices calling for the US to declare war on Germany, and the vast majority of Americans just did not want to get us suckered into another "foreign war" -- as President Wilson had done in 1917.
Net result: with Obama as with FDR, the US would stand by and watch as Hitler's armies conquered more and more of Europe.
Serious concern would not begin until Hitler eventually turned on his erstwhile ally, Uncle Joe. ;-)