"We're not talking about popularity, we're talking about the gun that comes to mind when you think of American spirit and will."
That's completely in the eye of the beholder, and how he chooses his symbols from his own experience.
Mind you, I have nothing whatever against the 1911. Brilliant design, powerful caliber, long associated with our military. That last factor alone sells it to many people as "America's handgun".
But generations of LEO's, countless Air Force and Navy pilots, many Vietnam War tunnel rats, and millions of civilians protecting their lives, homes and loved ones have used .38 Special revolvers, with the LEO's and lots of civilians often transitioning to .357 Magnum. I don't think you can rule out the fine Smith, Colt and Ruger wheel guns from consideration.
"Don't let macho be your epitaph."