Elizabeth WarrenElizabeth WarrenBipartisan senators to hold hearing on 'toxic conservatorships' amid Britney Spears controversy Senate advances Biden consumer bureau pick after panel logjam White House faces increased cries from allies on Haitian migrants MORE, the former White House official who built President Obama's Consumer Financial Protection Bureau from the ground up, announced her bid for Senate in Massachusetts on Wednesday.

"I'm going to do this.  I'm going to run for the United States Senate," Warren said in a video statement released on her website.

She made the sluggish economic recovery and its effect on working families the centerpiece of her message. "Middle class families have been chipped at, hacked at, and squeezed and hammered for a generation now and I don't think Washington gets it," she said, explaning her decision to enter the race.

"I grew up on the ragged edge of the middle class and I know its hard out there. I've fought all my life for working families and I've stood up to some pretty powerful interests. Those interests are going to line up against this campaign," she added.

Warren's focus on economic issues mirrored her comments in a statement released Tuesday. “The pressures on middle class families are worse than ever, but it is the big corporations that get their way in Washington,” Warren had said. “I want to change that.  I will work my heart out to earn the trust of the people of Massachusetts.”

Warren, a Democrat, had been widely expected to run against Sen. Scott Brown (R) for the seat, and had already started unofficially campaigning at events around Massachusetts. Brown's reelection campaign took some heat last week when it was revealed the campaign had purchased an Internet domain name mocking Warren.

A Warren adviser said she would greet Boston commuters Wednesday morning before traveling to the Massachusetts towns of New Bedform, Framingham, Worcester and Springfield.

Warren will enter the race on relatively solid footing. A poll conducted at the end of August by MassINC Polling Group for radio station WBUR showed 44 percent of likely voters choosing Brown and 35 percent choosing Warren.

But Brown has the benefit of high name recognition as the incumbent senator and a former state legislator. Forty-four percent of those polled said they were undecided or hadn't heard of Warren, compared to only 5 percent for Brown. He also has a massive war chest of about $10 million.

Although Warren will have to face at least five other Democrats in a primary before squaring off with Brown, none of the other candidates have the national stature or support of Warren, beloved by many Democrats as a tough advocate for consumer rights.

Democrats have been itching to take the seat back ever since Brown won it in a special election to replace Sen. Ted Kennedy (D-Mass.), who died in office after serving in the Senate for almost five decades. The win by Brown over Democrat Martha Coakley in the heavily Democratic state of Massachusetts was an embarrassment for the party and was largely attributed to a weak campaign run by Coakley.

This story was first posted on September 13th at 3:38 p.m.