I actually know certain facts about this matter, but am seeking guidance in interpreting these facts into "theories."
1) Theory 1, Economic: The Americans spent something like $2 billion (in money of the time) to build the atomic bomb. Germany simply did not have that level of resources, meaning that her initial lead in atomic understanding was moot. Like other areas (e.g. tank production), American economic power "swamped" Germany even though Germany had superior quality.
2) Theory 2, Scientific: The balance of (scientific) power was held by Jewish scientists like Einstein, Fermi (his wife was Jewish, not Fermi himself), and Bohr, meaning that Germany could have built the bomb if it had stayed on good terms with these people. Fermi and America's Robert Oppenheimer were referred to as the "fathers" of the atomic bomb. Einstein was the "grandfather" insofar his atomic theories paved the way for the others' work. Bohr was notable for what he DIDN'T do (correct the mistakes of his former student, Germany's Werner Heisenberg).
Do either theory alone or both theories together explain why America took the lead in atomic development? Are there other reasonable theories that I may have missed?
I am trying to check the validity of the comments I made in answering this other question. At the end of WWII, were nazis working on any other super weapon besides V-2?