Hindsight is always 20/20
Yeah the Lend&Lease stuff and so. OK my memory was wrong about Roosevelt and maybe the whole isolationist tendency was in the previous war.
I fully realize that the "Amerika-bomber" project was kind of sidenote and it never had real funding after 1939.
To add to that, even the mighty B-29 lacked the range to bomb Third Reich mainland from USA. Even for US economy, long-range bombing campaign could have been tough to handle.
In OTL, even if Third Reich could field enough bombers and somehow collect the fuel for the 20 plane raid (which would be at least week off from operations from some JG), after 1943 there would not be any effect.
So, hypothetically speaking, and ATL (Alternate TimeLine), for undisclosed reasons Luftwaffe fields in 1943 a FernKampfGeschwader of 4 gruppen with two of them equipped with bombers with suitable range to hit US east coast.
If this strike happens, what happens with the allies? Reducing the start of bombing campaign in ETO and less resources for MTO? US pulling back wings for homeland security?