Now he's sitting on more than $7 million in campaign cash. He's got a best-selling autobiography, "Against All Odds: My Life of Hardship, Fast Breaks and Second Chances" and he has emerged in recent polls as one of the most popular politicians in a state long dominated by Democrats.
"People in Massachusetts realize that Senator Brown is as strong as garlic," said Kaufman.
Brown has cast himself as a moderate, seeking to appeal to independents and conservative Democrats. Such support is vital for a Republican to survive in heavily Democratic-leaning Massachusetts. Democrats complain it's all a smokescreen to mask Brown's GOP loyalties.
Democrats were buoyed by how Massachusetts bucked the GOP tide in last fall's midterm elections. The party kept all 10 U.S. House seats and the governorship. Since 2012 is a presidential year, Democrats are hoping Obama's popularity in the state will hurt Brown.
But Marsh said Democrats still need to find a way to unite behind a strong challenger.
"Not to reduce myself to cliches here," she said, "but you can't beat somebody with nobody."