Senate candidate Elizabeth Warren speaks Saturday in Boston. Ms. Warren is running against Republican incumbent Sen. Scott P. Brown, who is now considered the underdog because she has linked him with Republican goals for a Democratic state. (Boston Herald via Associated Press)
Democratic U.S. Senate candidate Elizabeth Warren speaks during a campaign event at University of Massachusetts-Boston, Friday, Oct. 26, 2012. Warren is challenging incumbent Republican U.S. Sen. Scott Brown. (AP Photo/Elise Amendola)
Challenger Elizabeth Warren and incumbent Sen. Scott Brown promised to donate to charity if any outside groups advertised on their behalf. Direct mail, phone banks and canvassing efforts are allowed. (Associated Press)
Challenger Elizabeth Warren and incumbent Sen. Scott Brown promised to donate to charity if any outside groups advertised on their behalf. Direct mail, phone banks and canvassing efforts are allowed. (Associated Press)
** FILE ** These 2012 file photos show incumbent Sen. Scott Brown, R-Mass., left, and Democratic challenger Elizabeth Warren, in Boston. (AP File Photos)
Republican Sen. Scott Brown speaks during a debate with Democratic challenger Elizabeth Warren in Springfield, Mass., Wednesday, Oct. 10, 2012. (AP Photo/Elise Amendola)
Republican Sen. Scott Brown speaks during a debate with Democratic challenger Elizabeth Warren in Springfield, Mass., Wednesday, Oct. 10, 2012. (AP Photo/Elise Amendola)
Supporters of Republican incumbent Sen. Scott Brown and Democratic challenger Elizabeth Warren hold signs outside Symphony Hall in Springfield, Mass., Wednesday Oct. 10, 2012, prior to their third debate. (AP Photo/Elise Amendola)
Supporters of Republican incumbent Sen. Scott Brown and Democratic challenger Elizabeth Warren hold signs outside Symphony Hall in Springfield, Mass., Wednesday Oct. 10, 2012, prior to their third debate. (AP Photo/Elise Amendola)
