Tells the Wall Street Journal, "I think my run at public office is over." Says of his loss to McCain: "I'm a big boy. I understand how politics works."
Also says his much-criticized comment about his sons serving the country by helping his campaign was intended as a joke.
Romney one of three potential VP contenders to visit McCain's Arizona ranch this weekend.
Plus: Romney chairs new PAC, debuting Thursday, to help elect conservative Republicans. Read release here.
