Air superiority, then air supremacy supporting ground forces can be so overwhelming, especially (as some people reminded us) when large industrialized nations are the enemy.
If the Luftwaffe had continued to launch sorties against both the English coastal radar -helped by spotters etc- and the very critical RAF airfields, instead of switching primary tactical bombing to English cities as Vergeltung/vengeance for the RAF's first revenge attack on Berlin, the Germans might have kept US forces from later using England as a strategic "aircraft carrier" and vast, handy troop base.
It's doubtful, at least to me, that German divisions with Garands would have made much of a difference.
And the P-47's extremely tough, air-cooled radial engines (as with the airframe) were not nearly as vulnerable to overheating during strafing sorties as the 'water'-cooled P-51's engines when coolant was lost.
Last edited by Ignition Override; March 19, 2013 at 12:44 AM.