Why weren't Marines chosen for Normandy?

Army and the AAC were both under Eisenhower's charge, from how I understand it. It just wasn't the Corps' theatre. There WERE Marines involved in both the African and European theaters, just not nearly as much as with their brothers in the Pacific.

Because they were needed to fight it out on the beach.

Two things, 1) Army was also used extensively in the Pacific. My grandfather fought with one of the most used Divisions, the Sightseein' Sixth in New Guinea and the Philippines. 2) if I'm not mistaken, and I probably am, didn't the Army use Marine Advisors to help plan the Normandy invasion as well as landings elsewhere?

I think both branches did exceptionally well in the theaters and campaigns in which they were used.

Because the Marines operational theater was in the pacific the logistics of transferring them around the world for the Normandy invasion would have been to difficult, Also the army had been successful in other amphibious landings earlier in the war in North Africa and Italy.

Marines were all on the west coast and in the pacific

Because the Marine corps, which is a department of the Navy, was engaged in the Pacific Island hopping campaigns, and to stop without accomplishing the mission of securing the Pacific, would have led to disastrous consequences for America and ultimately the Allies in general.

Because we only had 6 Divisions compared to the Army's 89. We would be more useful in the Pacific campaign so it was there that we fought. However, Marines did train the Army for that landing, and there was a small force of Marines (I believe one company) that was in reserves for Omaha Beach, but they never got sent in for idiotic hubris-related reasons.

We have to leave something for the Army. ;)

Without googling - My thought is that we were already gearing up for war in the Pacific, many and major amphibious landings were anticipated, primarily a sea and air war and at the time, the Marines were the infantry of the Navy. Taking and occupying islands would need ground forces, hence Marines. The European theater was going to be primarily a ground and air war.

Just my assumptions.

Beyond the fact that the Marines were already involved in the Pacific; I think it also came down to numbers. Simply put, at the time, the Marines were the "newest" branch. Their numbers were small at the time when compared to the Army. The amount of people needed to take the beaches of Normandy were a lot higher than what the Marines could offer.

Not to say they couldn't do it, but I think the right call was made. Have the Marines stay and fight in the Pacific using their light and agile framework to jump from one little rock to the next in the middle of the Pacific while the Army could break into Europe and use their numbers to overwhelm the Axis Powers thus resulting in VE and shortly after VJ days.