Senator Elizabeth Warren
Photo: Andrew Harrer / Getty Images

Sen. Elizabeth Warren is throwing her fundraising muscle behind fellow Democratic Sen. Jeanne Shaheen who's facing a possible challenge from former Massachusetts Republican Sen. Scott Brown in New Hampshire.

    Warren defeated Brown in a 2012 race that was the costliest in Massachusetts history. She said in an email to supporters that they helped her raise $40,000 for Shaheen over the weekend.

    Warren faulted Brown for failing to agree to the so-called ``people's pledge'' in the New Hampshire race. Warren said Brown has ``signed on to get the dirtiest, most secretive help he can find'' to attack Shaheen.

    Brown and Warren signed a similar pledge in 2012, limiting the outside money spent on television, radio and internet ads.

    Brown has pointed to Shaheen's out-of-state fundraising, calling her demand for a pledge ``hypocritical and self-serving.''  (Associated Press)