The tug of war between Republicans and Democrats over the razor-thin majority in the Senate has carried through the decade and is expected to play out once again in next year's elections.
Democrats, for the second election cycle in a row, appear to have the advantage in the next 19 months before the November 2008 election, say political analysts, though most concede it is just too early to predict their success.
"I think Democrats clearly have the momentum coming out of the 2006 elections and the 2008 playing field allows them to start this cycle on offense," said Nathan Gonzales, editor of the Rothenberg Political Report, a Washington-based campaign tipsheet.
"It's still too early and we have to see who is going to run for election and who is not," Gonzales added.
Most Vulnerable Senate Seats in 2008
Thirty-three of the nation's 100 senators are up for re-election next year. Of them, 21 are Republicans, and 12 are Democrats. Currently, the Senate is comprised of 49 Republicans, 49 Democrats and two independents, Sens. Joe Lieberman of Connecticut and Bernie Sanders of Vermont, who caucus with Democrats.
Based on political prognostications from the experts, the following are the hot races to watch:
Arkansas: Republicans want to challenge one-term Democratic Sen. Mark Pryor, and if former Gov. Mike Huckabee drops out of his race for the Republican presidential nomination, they think he would be a formidable opponent.
Colorado: Sen. Wayne Allard has already announced his retirement and Republicans are still suffering from losses in the state in last year's midterm election. Rep. Mark Udall, now in his 5th term, has announced he will be seeking the Democratic nod. Former Republican Rep. Scott McInnis, considered a leading contender, recently announced he would not run.
Louisiana: Analysts say African American flight out of the state following Hurricane Katrina created a serious shift in political demographics there, and not in the Democrats' favor. As a result, two-term Sen. Mary Landrieu may be the most vulnerable Democrat in the Senate.
Maine: As a member of the "Gang of 14," the bipartisan group of moderate senators who dominated much of the 109th Senate, two-term Sen. Susan Collins would normally seem safe in the independently-minded state of Maine. Democrats smell vulnerability, however, and think six-term Rep. Tom Allen would make a sharp opponent.
Minnesota: Experts say one-term Sen. Norm Coleman joins a number of other Republican senators who may be in trouble for their party affiliation, war stance and loyalty to the Bush administration.
Nebraska. While speculation has largely centered on whether two-term Republican Sen. Chuck Hagel will run for president, much of the buzz is about whether he will seek re-election. If he does not, potential candidates on both sides of the aisle are looking to step in.
New Hampshire: Republicans here took a big hit in 2006, losing their two congressmen to Democrats. Analysts say they don’t think the bloodletting is over and Sen. John E. Sununu is vulnerable if Democrats can field the right candidate. Already, groups are putting out attack ads against the son of the former George H.W. Bush chief of staff.
Oregon: Two-term Republican Sen. Gordon Smith was one of the first Republicans to come out against Bush’s Iraq war policy and was one of two GOP senators — the other being Nebraska Sen. Chuck Hagel — to vote with the Democrats for a timeline to withdraw troops. Nonetheless, Democrats say he is vulnerable and have targeted this race, hoping Rep. Peter DeFazio might throw in his hat.
South Dakota: The health of Democratic Sen. Tim Johnson, 60, who is still recovering from a brain hemmorhage last December has left people guessing about whether he is well enough to run again. That decision will determine the level of excitement around this race.
Tipping the Scales
Political observers say persistent opposition to President Bush and the Iraq war, coupled with the seeming missteps made by the Republican administration over the last year, is bolstering Democratic prospects for seat gains, particularly in moderate or "purple" swing states.
On top of that, Democrats not only have fewer seats to defend, but are having an easier time attracting both top-tier candidates and cash. The Democratic Senatorial Campaign Committee outpaced the NRSC in fundraising $2.7 million to $2.4 million in the last quarter, according to recently released figures.
"I think the Republicans have a bit of a noose around with necks called 'George Bush,' and I think we have a number of strong candidates with a real range of experience," said Washington, D.C.-based Democratic pollster Celinda Lake. "And (Democrats) are showing a real ability to raise money."
"I think voters are more in step, more in line, with our position on the issues than they are with Republicans — same as in last (election) cycle," said DSCC spokesman Matt Miller. "They see Republicans standing in the way (of change)."
But Republicans aren't ready to cede that point, claiming they aren't the only ones to blame for the problems in Washington these days.
"I think it was very easy for voters to look at everything that was going wrong and blame Republicans because Republicans were in charge of everything — that’s not going to be the case this year," said Rebecca Fisher, communications director for the National Republican Senatorial Committee.
"We realize that we have a significant uphill climb ahead of us. We are well aware what we’re up against," Fisher said.
But, she added, GOP senators in states now targeted by Democrats — Minnesota, Oregon and Maine among them — will hold their own in the ensuing months.
"We think the voters really trust and like what those senators are doing in Congress, while they may not like what the Congress or the president are doing in general," said Fisher.
While so far Allard is the one to announce his retirement, no one believes he will be the only one in the coming year to announce an end to their Senate career.
Analysts point to Republican Sen. John Warner of Virginia, who is 80 years old, and Sen. Pete Domenici, R-N.M., who is currently embroiled in the scandal involving the firing of eight U.S. attorneys. Besides Johnson's health, observers are looking to plans by 74-year-old Sen. Craig Thomas, R-Wyo., who was diagnosed with leukemia shortly after the 2006 election.
Sens. Frank Lautenberg, 83, a Democrat from New Jersey, and Thad Cochran, 69, a Republican from Mississippi, have also been mentioned as potential retirees who could leave contentious campaign battles in their wake.
Most analysts emphasize that they aren't prepared to make any real predictions and stress that plenty of time remains for momentum to swing the other way.
"I think the Republicans have until about October or November to get their act together if they want to reverse the perception that people have of the party, then I think they can hold on," said Sean Evans, politics professor at Union University in Tennessee. Evans nonetheless warned if conditions in Iraq don't get better, and mistakes by the administration continue to hamper successes in the party, "the Republican brand is going to be damaged."