Nearly a month ago, Attorney General Martha Coakley, leading in the polls by a comfortable 30 points, seemed to be cruising over a little known Republican state senator, Scott Brown. Three days before the Massachusetts special election, the unthinkable has happened: Coakley and Brown find themselves in a foot race, in one of the most Democratic states in the nation, the home state of the ``liberal lion'' Edward Kennedy whose seat both candidates are vying for in which the stakes couldn't be higher. At stake is the decisive 60th vote in passing health care reform; a Brown upset presumably shatters President Obama's hope of signing into law a historic overhaul of nation's health care, something the late Senator Kennedy championed during his 47 distinguished years in the Senate. As far as New England comebacks go, a Brown victory on Tuesday would be akin to the Boston Red Sox storming back from a 0-3 deficit to the New York Yankees in the 2004 American League Championship Series to advance to the World Series for the first time since 1918. Edward Brooke, in 1967, was the last Massachusetts Republican elected to a U.S.