that has long been suggested - but AS has a very high Market cap.... one-third of DL's for an airline that is 1/10th the size.
AS is a publicly traded company so they would have a hard time saying they won't merge w/ someone if that company offers enough money.
I'm just not sure it is worth DL's while to acquire them.
DL pilots would just as soon see a lot more DL flights up and down the west coast instead of DL connecting passengers onto AS codeshare flights. LAX-SEA has got to be a large market for DL passengers on AS flights. I think the DL pilot contract requires them to get some type of reports w/ codeshare passengers (perhaps at a high level) on codeshare partners to ensure DL is not "overusing" those partners to avoid using DL aircraft and personnel.
hard to know what all is behind it but DL has made it clear that don't want to use their resources to help competitors. DL is in the process of cancelling ticketing agreements with several airlines - Turkish and Qatar - can't remember others - because DL connects a lot of passengers to those carriers only for them to undercut DL or Skyteam carriers due in part (or DL says) due to government subsidies. I dunno but when DL says they aren't going to allow their feed at JFK to help certain airlines, it does have some impact.
OTOH, DL should have no problem filling these extra flights during the summer anyway; they are starting 2 new int'l routes - HND and PVG - out of SEA this summer. What happens in the summer will say a lot more than the summer flights.
Size really doesn't matter when you talk about a few percent more here or there...AA, DL, and UA will all be approximately the same size. The real question is who is able to serve the most key markets; it is very possible to be smaller but still have better coverage of the most sought-after business markets.