How Massachusetts Senate race became so close

BOSTON - A Republican's surprising nimbleness, his opponent's missteps and shifting political winds in this "bluest of blue" Democratic state have turned a sure thing into an even bet.

Instead of Democrats easily retaining the Senate seat held for 47 years by Edward M. Kennedy, Tuesday the GOP may win the vote necessary to block President Barack Obama's agenda. Few could have dreamed this possible after the death of the Senate's "liberal lion" in August.

In a span of weeks, state Sen. Scott Brown has capitalized on voter dissatisfaction to erase a double-digit lead held by Democrat Martha Coakley, the state attorney general. He's done it by knocking on doors in conservative South Boston and by holding kitchen-table conversations with voters of all stripes across the state.

Coakley ran a textbook primary campaign, but stopped after winning the four-way primary with 47 percent of the vote. She disappeared from public view Christmas week, confident she needed only activists and their networks in what was projected to be a low-turnout election.

When she emerged, it was just to sit on the stage at inaugurations for newly elected Democratic mayors. There was no stumping, only news releases. And she balked at debates. When the final one a week ago ended, Brown had clearly won it.

While Coakley was cloistered, Brown launched the campaign ad war Dec. 30. The spot began with film of Kennedy's brother President John F. Kennedy arguing for an across-the-board tax cut, and ended with video of Brown completing the speech.

Coakley didn't respond in kind. She waited a week before airing her first campaign ad, and when she did, the spot focused on her career and work prosecuting child-sex offenders.