A suddenly populist Barack Obama tore into the Republicans for siding with banks rather than consumers and taxpayers Sunday in Boston, hoping that his fiery rhetoric would revive the candidacy of embattled Massachusetts Democratic Senate candidate Martha Coakley.

Coakley, who is in a tight race to fill the seat of the late Ted Kennedy, was not supposed to be in trouble in Tuesday’s special election. But late polls suggestthat Republican Scott Brown has moved even or perhaps ahead among likely voters in the usually blue state of Massachusetts.

Brown is in the running for two reasons: Coakley has run an exceptionally cautious campaign while the Republicans have succeeded in stirring anger over a health-care reform plan that seems to promise more in the way of bureaucracy and cost than real reform.

Of course, Brown is no reformer.

The former male model who now dresses in work-shirt drag and drives a pick-up truck is merely a savvy practitioner of the "party of no" strategy that Republicans have adopted going into a 2010 election cycle when they hope to reposition their party as an alternative for Americans who are frustrated by economic uncertainty and a sense that Washington is more interested in helping Wall Street than Main Street.

So Obama came to Massachusetts to stand squarely in the middle of Main Street.

Noting the fact that Brown has said he would oppose new taxes on big banks — many of which are recording high profits and paying record bonuses — Obama ripped into the Republican.

"We asked Martha’s opponent, what’s he going to do, and he decided to park his truck on Wall Street," Obama told 1,500 cheering Coakley backers. "Let me be clear: Bankers don’t need another vote in the United States Senate. They’ve got plenty."

The president is hoping that populism will turn the tide for Coakley and save the 60th seat in the Senate for Democrats.

If it does, the turn of the Democrats toward the politics of William Jennings Bryan will deserve a good deal of the credit. Let’s just hope they remember that it was rabble-rousing, not caution and compromise, that did the job.

If Coakley loses, it will not be because the Massachusetts voters who so recently elected Ted Kennedy and Barney Frank have suddenly become tea partiers. Rather, it will be because Democrats and liberal independents couldn’t be roused to vote for the party of a president who was too slow to focus on the economy and jobs — and a populist promise to put Americans back to work before putting speculators and CEOs back in the high life.