One of his TV ads seemed to revive doubts about his too-perfect life — an issue that had hurt his Senate candidacy after Ann said they had never had an argument. Called "Ann," the spot featured the Romneys talking about their storybook romance and family. Ann said Mitt was "very romantic" on their first date, a prom. Mitt professed his love for his wife ("Ann's just good to the core"). It closed with video of Mitt in a bathing suit, horsing around with his sons on a raft at the lake.

Romney's poll numbers tumbled.

Three weeks into the seven-week general-election campaign, he trailed O'Brien by 10 points in his own tracking. Internally, some advisers thought the cloying tone of the ad encased the candidate in plastic.

"I think it made ((Mitt)) appear to be too perfect," recalled Murphy, the irreverent strategist and media consultant who crafted the ad and insisted it would have worked in any other state. "There's a certain cynicism in the Massachusetts electorate, and it locked into that."

In the next four weeks, however, Romney climbed back into the race — helped by O'Brien, who made two blunders that eroded her centrist image. She embraced gay marriage — a year before the Supreme Judicial Court ordered it — and, in the final debate, endorsed a lower age of 16 for abortions without parental consent.

Murphy, meanwhile, produced two devastating ads that featured a "watchdog," Duncan the basset hound, snoozing as men removed bags of money from the state treasury. Using humor, the ads fused loosely related issues, including $7 billion in state pension fund losses in the stock market crash on O'Brien's watch and the lobbying work of O'Brien's husband, to shake her credentials as a manager and cast her as an insider.

O'Brien called the ad "as disgraceful as it is inaccurate," but it worked. At the same time, O'Brien's ads exhumed the robber-baron line of attack from the 1994 race, one featuring a steelworker who lost a job in a shutdown of a Kansas City plant bought by Bain Capital. Romney, however, was in Utah, running the Olympics at the time.

"It was the Ted Kennedy punch, but it was gone," Michael Travaglini, O'Brien's chief deputy, recalled. "The Olympics had made Mitt a real celebrity. That carried significant weight, and it made him more credible."

On Nov. 5, the Romney-Healey ticket romped, defeating O'Brien and her running mate, Christopher Gabrieli, by 106,000 votes, or 5 percent, of 2.2 million cast. The Republicans held their tiny base, swept the independent-rich towns of the I-495 crescent, and held down Democratic margins in the urban strongholds.

Forty years after George Romney won his first election, his son had captured his first political office. Both were 55 when elected governor.