I like how this thread turned from being about a mass shooting to gun control to semantics and nitpicking. It's not smoke, it's tear gas. If the shooter could see well enough to pick off individual targets, some person in a given row could aim near the attacker without a civilian getting in the way because of stadium seating
I feel stupid posting thrice but this a really unreasonable assumption.
Variables in the theater that would make this really difficult:
--Fear (anyone in that situation would be incredibly afraid and would have difficulty controlling themselves or their actions unless they are a police officer with many years of combat/emergency experience)
--Other people (are running into you, screaming, being loud, etc)
--Tear gas, and here I'll quote from wikipedia (I don't know what type of grenade James Holmes used and couldn't find anything online -- if someone knows feel free to correct me or edit this post)
"Tear gas works by irritating mucous membranes in the eyes, nose, mouth and lungs, and causes crying, sneezing, coughing, difficulty breathing, pain in the eyes, temporary blindness, etc. "
-- call me crazy, but this makes it difficult to even see or breathe, let alone operate weaponry with any degree of accuracy
--Bullets (small pieces of lethal metal are flying through the frenzied throng of bodies, killing whomever they strike)
--The fact that the gunman is wearing body armor with only several places in which he could potentially be wounded (not discounting the fact that in a theater with 100+ seats and many people moving the chances of hitting another body over the gunman are very very high, and taking into consideration the fact that even if you hit the guy he might not necessarily stop, slow down, it might nick him, etc...)
I was unfortunately not able to find a picture of the seating arrangement in the aurora theater, but "stadium seating" wouldn't be super helpful in all probability -- it would depend on the size of the theater and the slope of the seating, and even with a huge slope, the other factors and the fact that you'd have to be crazy or very very confident in your marksmanship skills to consider fighting over running away make your assumption inane. It's much easier to pick out individual targets (and I'm not even sure the shooter did this...didn't he just spray the crowd?) if you're the one who's doing the attacking (and defense, even with a firearm, is still inhibited by all the above factors).
I realize the argument over the hypotheticals of this scenario is intrinsically stupid and distracting, but I just wanted to assert that "defense" in this case is way more difficult, dangerous, and likely to cause further deaths than you seem to think. Don't complain about the direction the thread's taken -- you referred to the scenario twice and it is essentially a microcosm of the larger argument (i.e. whether looser gun laws give people protection from violence).