[PHX31]

Mesa does have the light rail line, and it's downtown is becoming more popular and getting a big facelift. I understand the question and think it's a possibility. But it would be so far into the future that twin cities would be the norm everywhere.

As said, Tempe almost already is becoming a twin city (it has a booming skyline, ASU, light rail, and a walkable core), and Scottsdale is more popular as a tourist destination, plus a lot of the money of the metro is over there. The downtown area is a night life spot, has some residential (mostly high end), and some offices, but I doubt it will ever be more than that. Those 2 are much bigger players in the metro area as compared to Mesa, although they don't have the population.

And the satellite cities around Phoenix (Tempe, Mesa, etc.) aren't just suburbs in the normal sense, they started out as their own places, and have grown together. Similar to all of the various "suburb" cities around Los Angeles.