Lets see,
#1 it depends on where you hunt
#2 it depends on how you hunt
#3 it depends on how you shoot.
#4 it depends on whats legal.
#1 Deer vary greatly in size, and size is more of the issue than the breed. A south texas deer, might weigh in at 75 pounds, dressed. A northern UP or Minnesota deer might run 275 or more dressed.
#2, are you shooting bean field deer at 500 yards? Are you hunting Alder thickets and Aspen sprouts, where you are going to jump deer and have to anchor them while they are running? Are you sitting in a stand in an orchard, picking and choosing and then popping the one you want?
#3 Do you shoot running deer, do you shoot for the head, neck or aim for body shots, heart lungs ?
#4 its all moot if your state says 6 mm and up or something similar.
Personally I think deer hunting should require larger than 6 mm, not inclusive. but thats me.
Now, I hate interfering regulations too, and thus i am happy that for example my .22 hornet is now legal for shooting in this state. (mn) simply because common sense should rule, but then I see guys buying sledgehammer rounds for their .338 winmag or people here who think a 375 is not big enough for water jugs, and I get willing to say that you can hunt deer with anything that has between 1750 muzzle energy and 3200 fp of muzzle energy.
mostly I think its a matter of how you look at yourself as a hunter.
I tend to think of myself as a very restrained hunter who only wants to shoot what i know I can kill, and I want to leave as much left for eating as possible, thus, blowing huge holes in the animal, leaving massive ammounts of meat blood shot are just as revolting to me, as shooting and hitting an animal with a gun that does not have enough pop to kill it cleanly and finding I have a wounded animal under stress that I will not find until much later, which has loaded its meat with all sorts of by products of stress and injury.