Liberal firebrand Elizabeth Warren raised $5.7 million in the last quarter of 2011, a number that not only eclipses her rival's fundraising effort but underscores Democrats' desire in Massachusetts to take back the Senate seat once held by the late Ted Kennedy.

Warren's campaign says 23,000 people in Massachusetts have donated money, and that the average contribution is $64. Her $5.7 million haul between October and December is impressive for a Senate candidate - and is even more than some Republican presidential candidates have raised in past quarters.

Warren, a former financial adviser to President Obama, is looking to unseat Scott Brown, who raised $3.2 million in the last quarter of the year. He also raised $1.4 million in the third quarter and has more than $10 million on hand.

Brown raised $15 million and spent about half of that to beat Martha Coakley in the special election for Kennedy's seat, according to federal campaign finance records from the period ending shortly after the vote.