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Democrats could end up controlling 60 seats in the U.S. Senate for the first time in a generation. That would be a filibuster-proof majority, one that could stop the opposition from blocking legislation.
The last president to enjoy that advantage was Jimmy Carter.
In key states Tuesday, voters went to the polls in record numbers as Democrats and Republicans fought hard over control of the U.S. Senate.
Most analysts predict Democrats will easily add to their 51-seat majority (including two independents), but fall several short of the magic number.
"As for 60, that's very, very difficult," Sen. Charles Schumer, told CBS's Face the Nation on Sunday. Schumer runs the Senate Democrats' campaign committee. "It's possible, but unlikely."
Thirty-five seats are at stake Tuesday. The Republicans are defending 23 seats, the Democrats just 12.
Democrats are focusing on 12 races where they hope to make gains. The party is expected to win at least two without much trouble.
One is in Virginia, where former Democratic Gov. Mark Warner is favored to beat former Republican Gov. Jim Gilmore for the seat of retiring Republican Sen. John Warner. The other is in New Mexico, where Democratic Rep. Tom Udall is favored to beat Republican Rep. Steve Pearce to win the seat left open by retiring Republican Sen. Pete Domenici.
The next group of races the Democrats are eyeing appear to be leaning in the party's favor and involve some big political names who, in ordinary times, might have nothing to worry about.
They include Republican Elizabeth Dole — the two-time Cabinet secretary and wife of former Kansas senator and presidential candidate Bob Dole — who is fighting a surprisingly tough campaign in North Carolina against Democratic state Sen. Kay Hagan.
One of the flashpoints in the race was a Hagan ad featuring two old men in rocking chairs who alluded to Dole's age, 72, and tried to portray her as past her prime. Dole fought back with an ad tying Hagan to a group of atheists, but the spot seems to have boomeranged.
"The backlash on this has been as resounding as any we have ever seen," said Bob Benenson, politics editor at Congressional Quarterly. "Almost every major newspaper in the state of North Carolina has just blasted Dole for these ads."
Another well-known politician, Alaska Republican Ted Stevens, could well lose his seat because of recent convictions for lying on financial disclosure forms. Stevens did not reveal that workers for an oil services company did major renovations on his Alaska home.
Stevens faces Mark Begich, the Democratic mayor of Anchorage. Without his legal troubles, the 84-year-old senator would probably be hard to beat. He's represented Alaska for almost 40 years and is known there as "Uncle Ted."
In New Hampshire, Republican John Sununu — whose father was governor and chief of staff to President George H.W. Bush — is in a tough rematch against former Democratic Gov. Jeanne Shaheen. State election officials said voting is heavy and New Hampshire may be headed for a record-setting turnout.
In Nashua, N.H., 53-year-old Beth Ragan said she doesn't believe the Democrats have a lock on the state. "If that was true, why were (the Clintons) here? They wouldn't have been sent here, they would have just said, 'We've got New Hampshire, let's move on.' "
While polls have shown a consistent lead for Democrats Barack Obama and Shaheen, Republicans continued to work the phones Tuesday in an effort to motivate GOP voters.
In Colorado, Democratic Rep. Mark Udall — son of the late Arizona Rep. Morris Udall — appears to have an edge over former Republican Rep. Bob Schaffer. The two are fighting over the seat left vacant by GOP Rep. Wayne Allard, who is retiring after two terms. And in Oregon, Republican Sen. Gordon Smith is up against the state's Democratic House Speaker Jeff Merkley. In a sign of the times and the challenges Republicans face, Smith went so far as to compliment Obama in a recent debate.
But Democratic Party volunteers urged voters not to be complacent.
The Democrats' Uphill Battles
Democrats are focusing on five other races that will be harder to win: They are all seen as leaning Republican.
The marquee contest among this batch is Minnesota, a three-way race among Democrat and former Saturday Night Live satirist Al Franken, first-term Republican Sen. Norm Coleman and Dean Barkley, an independent.
Franken enjoys huge name recognition from his TV days. But they came back to haunt him when Republicans pulled an excerpt from an old magazine story that quoted Franken making a joking reference to rape while thinking through a comedy sketch.
Another potentially pivotal race where Republicans are seen to have an advantage is Kentucky. Democrats would love to knock off Senate Minority Leader Mitch McConnell, who blocked many of the party's initiatives in the past two years. McConnell is up against Democrat Bruce Lunsford, a wealthy businessman.
Democrats are also looking for payback in Georgia.
First-term Republican Saxby Chambliss is going up against Jim Martin, a former Democratic state senator. Democrats are still bitter over Chambliss' 2002 campaign, in which he tried to portray the then-incumbent, Max Cleland, as soft on national defense. Cleland is a Vietnam War veteran and triple amputee.
In Mississippi, Democrats are trying to buck more than a quarter-century of Republican dominance. Former Democratic Gov. Ronnie Musgrove is trying to win a special election against Republican incumbent Roger Wicker. Wicker was appointed to the job last year after the resignation of Trent Lott.
Democrats also face an uphill battle in Maine, where they are hoping to knock off Republican Susan Collins, a two-term incumbent who is known for taking bipartisan positions in Washington. Collins is trying to hold onto her job against Democratic Rep. Tom Allen.
Unpopular President, Troubled Economy
That the Democrats face such a target-rich environment is a testament to just how bad things are for Republicans. The GOP is saddled with a deeply unpopular president. In terms of money, Senate Democrats have spent nearly twice as much as Senate Republicans.
But the reason some of these seats are even within reach now is because of the economy. Consider: In the first half of September, Republicans were fairly optimistic. Alaska Gov. Sarah Palin had just galvanized the GOP base at the Republican National Convention, and Sen. John McCain was ahead in some polls.
Nevada Sen. John Ensign, who runs the Senate Republican campaign committee, spoke hopefully of limiting losses in the Senate to just a few seats.
But after the fall of the investment bank Lehman Brothers and the bailout of AIG, the nation became consumed by the biggest financial crisis since the Great Depression. And the GOP never recovered. Over the weekend, Ensign called the financial crisis "a body blow" to Republican chances.
"When the economy is bad, it always works against the interests of the party in the White House," said Benenson of Congressional Quarterly.
"The American public — for right or wrong — attributes most of the responsibility for economic problems to the president's party."
Benenson says that although the financial crisis helped Democrats, the party laid the groundwork to take advantage of something like this years earlier. He credits Howard Dean, the head of the Democratic National Committee, for recruiting good candidates and targeting Republican states. He also says a similar, aggressive strategy by Obama has helped down-ticket candidates like Kay Hagan in North Carolina.
But even if Democrats have an extraordinary night and pick up the nine seats they need for a supermajority, they may not be able to ram through an agenda. For one thing, they would have to rely on Sen. Joe Lieberman as one of their 60. The former Democratic vice-presidential candidate is a pariah among Democrats and spoke on behalf of McCain at the Republican convention.
History suggests that filibuster-proof majorities often work better on paper than on Capitol Hill. Ask President Franklin Roosevelt.
He had an overwhelming majority in the Senate in the mid-1930s, but couldn't pack the Supreme Court because of opposition from Southerners in his own party. President John Kennedy had 65 Democrats in the Senate, but couldn't get his civil rights bill called up for a vote.
"The numbers can be very beguiling," says Ross Baker, a professor of political science at Rutgers University. But, he added, they often don't prove to be quite as valuable as they appear.