So I know the answer is no, but I'd save a nice bit of miles/money... How bad of an idea is it to do MEX-DFW on AA then buy a separate ticket on AS? I can either do a 2 or 4 hour layover version. The answer is it's bad I know, but how bad?
The MEX-DFW leg is nice and cheap, and I'm 75K on AS with lots of upgrade space available. So the flight back would be pretty low and net me some AS miles versus blowing a lot of Amex MR or cash for an airline where I don't accumulate miles frequently (e.g. DL or AA).