Our friendship began that night, as we talked about the sport of politics and walked around the mule corrals near the old hotel. She broadcast a bright interest in who I was and showed a touch of bemusement with her surroundings. She made friends as easily as other people breathe. She once told me that the best part of running for office was having a built-in excuse to approach strangers she wanted to talk with.

Gabby -- the nickname she enjoyed -- had grown up on Tucson's far-east side, in the family that owned El Campo Tire & Service, a local chain that branded itself "The Buck-Stretcher" in TV ads familiar to everyone in town. Her grandfather started the company as a single gas station in 1949; the son of a rabbi from Lithuania, he changed his name from Akiba Hornstien to Gif Giffords to avoid anti-Semitism. His son, Spencer, helped the company become successful; its many outlets featured service bays with brick arches that framed the windows in a Taco Bell style. "El Campo" is Spanish for "The Countryside," and the company sold a lot of tires to Latino customers in Arizona and Mexico. Gabby's mother, Gloria -- nicknamed Jinx -- is a bespectacled art conservator who loves to show off her extensive collection of Southwestern art as well as her own oil paintings.

Gabby laughed about her last name. It sounded friendly and breezy, and was both the product of her grandfather's whimsy and proof of the American capacity for reinvention. She earned degrees in Latin American studies, sociology and urban planning at Scripps College in Southern California and Cornell University in upstate New York, where she played up her Arizona cowgirl heritage by wearing vests and cowboy boots to class. She came home to run her family's tire company when her father needed to slow down, and then began her political career by serving in the state Legislature from 2001 until 2005. The Arizona chapter of Mental Health America named her legislator of the year in 2004, partly for her work on a bill to prohibit insurers from cutting back on treatment of the mentally ill. (The Legislature refused to pass the bill.) When she quit to run for the congressional seat that Kolbe left open, I put my writing career on hold to work for her 2006 campaign, going door-to-door to talk with voters. When Gabby won, I visited her new office in Washington, D.C., and stayed overnight in her small apartment near Capitol Hill while she was away on business. I left her a few housewarming gifts, including a six-pack of Negro Modela beer with a blue index card taped to it, on which I wrote: "For Emergencies Only." Three years later, I swung through D.C. again when she was out of town and borrowed the keys to her apartment. That same pack of beer was inside the fridge, untouched, with the note still attached.

Congresswoman Giffords was still Gabby from down the block, and our friendship endured. She took me to the phone bank at the Democratic Congressional Campaign Committee and we lamented the scene: rows of cubicles with telephones on bare white desks, where members of Congress were supposed to dial for dollars in their free time. Later, at a cocktail fundraiser in a rich Democrat's apartment in New York City, she pulled me into the granite bathroom to show me her diamond engagement ring: Mark Kelly, an astronaut she'd been dating, had proposed to her just that afternoon. At that moment, she was giddy and nervous, but her speech to the crowd several minutes later was calm and measured. I attended her wedding in 2008 at an organic vegetable garden south of Tucson. Her gown was made from recycled material, and a line of Navy officers in dress whites saluted the couple with drawn swords. And then, in 2010, I paused my writing career again to work on her re-election campaign, in one of the nastiest elections I'd ever observed.

Gabby refused to demonize or dismiss her political opponents, even the obstructionists in the Arizona Legislature and Congress. She sought the kind of incremental change that comes through sweat and compromise, rather than indulging in grand, futile gestures. She supported solar energy, backed sane immigration reform that would reduce the number of immigrants dying in the desert, fought to make sure that federal college scholarships survived the budget cuts. I rarely asked her about congressional process; I figured she got enough of that elsewhere. "Awww," she would say at the end of each phone conversation. "I miss you. When do I get to see you again?"

The fact that Arizona could produce such a wonderful person, and such a wonderful politician, justifies holding onto some optimism about the state -- and by extension, some optimism about the nation as a whole. Another bit of optimism can be found in the behavior of the people around Gabby on the day she was shot. In that bloody moment, with no time to think, some of them stepped in front of bullets to save loved ones, suffering serious and even fatal wounds. Amid all the chaos and horror, people took the crucial steps that saved Gabby's life despite the bullet that tore through her brain. They formed a community on the spot, one stitched together by bullets.