American is about the only airline without a US alliance partner. Mergers are risky. US Air acquired PSA in California and that was a disaster so you wonder about America West. Acquisition of the TWA St. Louis hub made little sense because it did not attract more traffic.
Going back to Raleigh to provide more East coast service or forming a code-share alliance with Air Tran could make some sense? Based on the East coast using AA can be inconvenient, unless you live in Miami or Fort Lauderdale.
I think a lot more passengers would use AA if it had more East coast ties, but definitely no merger.