What sources support that (besides Time Man Of The Year 1938)
That’s simply not true. The US began providing Lend-Lease aid to the USSR in 1941 before entering the war.
I mean before the Nazis invaded the USSR. Public opinion was very anti-Soviet before then.
Anti-Soviet, but still more anti-Nazi. Worth remembering that in the UK the populace was far and away supportive of close ties to the Soviets even after the Pact was signed. There was a downturn for the Winter War but then an uptick again. France however did go off the deep end.