To anyone that dosent know, in an alternate timeline, Kennedy is assassinated by a bricklayer and Huey Long becomes president of the US. He proceeds to strugglingly keep US out of WW2, which makes Operation Sea Lion, Nazi Germany's attempt to invade Britian, successful.
I wanted to know how plausible was this in a alternate WW2 timeline? I suppose the US was relatively cool until Pearl Harbor, but did Britian really need the Unites States' help to fend off enemies from the southeast?