The U.S. Senate is sometimes called "the world's greatest deliberative body." Candidates spend small fortunes to get elected to the Senate.

There are only 100 members and they are considered among the most influential people in the federal government.

But, Massachusetts voters don't seem all that impressed.

There is a special election campaign going on to fill the late Sen. Edward Kennedy's seat, and voters are all but ignoring it.

A public opinion poll last week found that 93 percent of voters could not identify Dec. 8 as the date of a special primary election to pick the party nominees for the Senate. Many of the candidates are largely unknown despite millions of dollars spent on television advertising.

Local officials said they are surprised by the apathy.

"It seems to me we are being inundated with ads. I don't know how people cannot know," said state Rep. Betty Poirier, R-North Attleboro.

"We're all kind of dumbfounded by it," said state Rep. Bill Bowles, D-Attleboro.

The primary election features state Attorney General Martha Coakley, U.S. Rep. Michael Capuano, businessman Stephen Pagliuca and City Year founder Alan Khazei in the Democratic race.

State Sen. Scott Brown, R-Wrentham, and attorney Jack E. Robinson are the Republican candidates.

Newspapers have given the race constant coverage and there have been a number of forums on the Democratic side. Secretary of State William Galvin is running radio advertisements publicizing the primary, but the public has yet to warm up to the campaign.

Today is the last day to register to vote for the primary and local elections offices and town clerks will stay open until 8 p.m., but officials are not expecting a last-minute rush of interest.

Attleboro election official Mary Ann Drain and Foxboro Town Clerk Robert Cutler said they have not seen much activity from voters.

Former state Rep. Stephen Karol said the timing of the special primary could not be worse, and probably is a factor in the apathy. The Dec. 8 primary comes between Thanksgiving and Christmas, when voters have their minds of other things, he said.

"People just aren't focused on it. It's the time of year. And there is nothing else on the ballot," he said.

Danielle Fish of Mansfield, a Republican State Committee member, said voters should realize how important the election is.

A Democratic victory in Massachusetts would mean the party would have 60 votes in the Senate and have the ability to prevent a fillibuster.

She said if voters do not come out in large numbers, they will be leaving it to party insiders to pick the candidates.

"I truly hope voters remember this isn't 'Ted Kennedy's seat.' It's the people's seat. This is a rare and important opportunity for us to choose a voice for the people in the commonwealth. We must choose wisely and pay attention, and not leave it to special interests or legacy," Fish said.

Fish and others said a low voter turnout means the candidates with the strongest grassroots organizations will have the advantage.

"It all comes down to who gets out their vote," Karol said.

Bowles said the low turnout could mean the polls showing Coakley with a large lead are inaccurate because many of those supporters will not show up on election day.