Elizabeth Warren formally exploring Senate bid

Updated at 2:46 p.m. ET

Harvard Law professor and consumer advocate Elizabeth Warren took formal steps Thursday to explore a potential 2012 Senate bid in Massachusetts.

Warren has formed an exploratory campaign committee and set up the website elizabethforma.com to solicit donations.

Best known for helping President Obama set up the new Consumer Financial Protection Bureau as part of the president's package of Wall Street reforms, Warren has become a champion of liberals who want to unseat Republican Sen. Scott Brown.

Brown won the seat previously held by the late Sen. Ted Kennedy in a 2010 special election. Seven Democrats have already declared they're running against Brown, but some liberals see Warren as the best choice to go head-to-head against the Republican.

Emily's List, an organization dedicated to electing pro-choice Democratic women, released a statement praising Warren's possible entry into the race.

"The EMILY's List community has been telling me loud and clear that they want Elizabeth Warren in the race to beat Scott Brown," said Emily's List president Stephanie Schriock. "Elizabeth is strong, smart, and a dedicated fighter for working Americans."

The Progressive Change Campaign Committee has already raised $100,000 for Warren's potential campaign, and Brown has taken note. His campaign released a fundraising solicitation asking his supporters to help "fight back" against the Warren supoprters, saying that she stands for the "far left wing agenda for America - higher taxes, bigger government and more spending."

Brown could be a challenging opponent for Warren -- the senator had nearly $10 million in cash on hand at the end of the second quarter this year, and Warren has no experience in elected office and is untested as a candidate.

Warren has been engaging in a "listening tour" of Massachusetts this week, the Boston Globe reports. Earlier this month, she promised to spend time listening to Bay State voters before deciding whether to run for Senate.

Update: The National Republican Senatorial Committee released a statement brushing off Warren's potential candidacy.

"As a native of Oklahoma, the anointed candidate of the Washington establishment, and someone who has spent many years ensconced in the hallways of Harvard, it's a good idea for Professor Warren to learn more about her adopted state of Massachusetts as she prepares to compete in a crowded Democrat primary," said NRSC spokesman Brian Walsh.