CBS News Congressional correspondent Nancy Cordes reports that Republicans are feeling increasingly confident that they can pull off a major upset, one that would put a big dent in President Obama's ability to enact his agenda.
Until just a few weeks ago Democratic candidate Martha Coakley, the Massachusetts Attorney General, was considered a shoo-in. The seat she's seeking has been in Democratic hands since 1962. But a spate of recent polls, including a new Suffolk University survey, show her losing to Republican candidate Scott Brown by four points.
Brown has made stopping the health care reform bill a signature issue - a message that seems to be resonating with voters.
"Come Tuesday we're gonna send a thunder clap to let people know, not only here in Massachusetts but the people in Washington, that they're tired and we're tired of business as usual in Washington," Brown said.
If Coakley losses this race, Democrats will also lose their super majority in the Senate - meaning they would lose their ability to block any Republican filibuster on Democratic bills, like health care reform, thus putting the brakes on the President's legislative agenda.
"It would be just latest in a series of really eyebrow-raising indications that the public is tiring of the show they are seeing in Washington," said Jon Keller, a political analyst for CBS Station WBZ in Boston.
Democrats decided late last week to send in the president.
Rightly or wrongly, this race is being seen as a referendum on President Obama, who traveled to Massachusetts Sunday to campaign for Coakley.
"I'm here to tell you Martha Coakley is the person for that job," he told a cheering audience.
Because the stakes are so high, money is pouring in from out-of-state groups. The U.S. Chamber of Commerce (which opposes the health care reform bill) spent a half-million dollars on television advertising supporting the Republican Brown, while the Democratic-leaning League of Conservation Voters has given the Coakley campaign $350,000.
In the end, most political analysts expect the outcome to hinge on turnout. Statewide there are three times as many registered Democrats as there are Republicans.
However, 51% of Massachusetts residents consider themselves Independents.
Ramping Up the GOTV
Voter turnout is normally low in special elections, but even in staunchly Democratic Massachusetts, apprehension about President Obama's health care overhaul is fueling a huge wave of populist support for Brown.
Preparing for the worst, the White House and Democratic allies in Washington tried to plot a way to salvage their health care package if Brown wins. One scenario would push House Democrats to accept the health care bill the Senate passed last month even though it offers fewer people coverage.
Trying to wrest back the populist mantle, Mr. Obama told supporters Sunday that a vote for Brown was a vote to protect Wall Street at the expense of ordinary Americans. The president last week proposed
a tax on banks to close a deficit in a bailout fund they and automakers tapped during the financial crisis. Brown and other Republicans oppose the tax, saying it will trickle down to consumers.
Democrats insist that the new assault on Wall Street is working, and that voters have started to respond. Party officials said 3,500 campaign volunteers contacted 575,000 voters on Saturday alone, and they claim a 15-percent increase in likely Democratic participation since Friday.
GOP leaders nationwide asked supporters to pitch in to help Brown's campaign.
Former Massachusetts Gov. Mitt Romney sent out an e-mail asking his backers to make calls on Brown's behalf, even though Brown has largely distanced himself from Romney, whose popularity has ebbed in the state.
Former Bush White House adviser Karl Rove used his Twitter account to link to a phone-bank site, while Sen. John McCain, Obama's rival in the 2008 presidential contest, is promoting Brown on his political action committee's Web site.
The two GOP rivals for a Florida Senate seat, Charlie Crist and Marco Rubio, both urged their supporters to get involved in Brown's campaign.
The Coakley and Brown campaigns also were bombarding supporters with automated phone calls. The Democrats used appeals from Clinton and Obama, while Republicans have relied on calls from Brown himself and beloved Boston Red Sox pitcher Curt Schilling.
Concern among Democrats about turnout has been palpable. At a largely black church service Sunday, Boston Mayor Thomas M. Menino implored congregants to call at least 10 friends and make sure they planned to vote Tuesday.
At a Coakley rally in Hyannis Sunday, state Senate President Therese Murray went the high-tech route. "We need you on Facebook, on YouTube, on e-mail, texting ... however you communicate," she said, encouraging supporters to use those tools as a way to get their friends to show up at the polls.
Snowfall could be a concern: The National Weather Service said up to 8 inches will fall in parts of the state by midday Monday. Massachusetts Secretary of State William Galvin said late Sunday that he was working with the state's Emergency Management Agency to ensure voters have access to all polling places Tuesday.
Coakley and Brown were expected to start their last day of the campaign together, at a breakfast honoring the late Rev. Martin Luther King on the national holiday commemorating the civil rights leader's birthday. Coakley was then headed to campaign events in western Massachusetts, while Brown planned to wrap up with a rally in his hometown of Wrentham.