The Politico raises the comparison between the current Massachusetts race and the 1991 Senate race in which liberal Harris Wofford upset George H. W. Bush's attorney general Richard Thornburgh. Thornburgh was heavily favored, but lost to Wofford and his then little-known campaign manager James Carville, as Wofford hammered Thornburgh on the health-care issue. The GOP was shell-shocked by the loss, which served as a preview of both the Democratic strategy and the anti-GOP results of the 1992 election that brought us Bill Clinton.
Of course, Brown has to win for the comparison to hold, but expect similar shockwaves, this time on the Democratic side of the aisle, if he does.