With his wife, Gabby Giffords, my former representative, a survivor of an attack at a congressional meet and greet outside a supermarket in Tucson, he'll be able to advocate strongly for gun control. His living with the aftermath will make some people shut up and listen.
Also, our governor will not replace him with an idiot. We'd still have a Democratic senator representing Arizona.
Arizona is probably going to turn blue (not sure how bright the blue will be) because of an item on the ballot to make abortion access part of the Arizona constitution. It should greatly increase Democratic turnout in November.