Senators fled town one week early for what is shaping up to be a nail-biter midterm election with Republicans poised to pick up a significant number of seats, according to the experts, and the outcome could have more of an immediate impact on legislation than most people think.

There are three special elections this cycle that will result in the winners being seated immediately for a lame duck session set to begin November 15, and depending on the outcome of those highly-contested races, the fate of the majority's agenda could be very much in jeopardy.

Majority Leader Harry Reid, D-Nev., prioritized food safety and energy legislation for the session, but the real fight is looming over whether or not to extend the expiring Bush tax cuts and what to do about the 12 annual spending bills.

With the Supreme Court's recent refusal to block a lower court's ruling that set up a special election for President Obama's former Senate seat, appointed Sen. Roland Burris, D-Ill, joins two other Democratic appointees who are now officially retired: Sens. Ted Kaufman, D-Del., and West Virginia's shortest tenured senator, Carte Goodwin, a Democrat appointed to replace the late Robert C. Byrd.

In Illinois, the Democrat, Alexi Giannoulias, advocates a return of higher tax rates for the wealthy, a position favored by Reid and the White House. "Republicans (and some Democrats) are holding middle class tax cuts hostage unless the top 2% of Americans get a massive new tax break. I strongly oppose any efforts to deprive the middle class of much-needed tax relief," the Democrat says on his website.

Meanwhile, Rep. Mark Kirk, the Republican challenger in that race, supports extending all of the Bush tax cuts and, in fact, repeatedly touts his record of cutting taxes 40 times. Kirk, who is up slightly in a Real Clear Politics average of polls, is already promising Illinois voters in this television ad that should they return him to Washington as the "42nd senator," he won't vote for anything during the lame duck, warning against a possible VAT tax, the so-called "card check" legislation that makes unionizing easier, and "a huge all in one spending bill riddled with earmarks."

Democrats deny these measures are on the agenda for the lame duck.

West Virginia's popular Democratic governor, Joe Manchin, who is now in a "toss up" race for the Senate seat against wealthy businessman John Raese, according to Cook Political Report, broke the news first to Fox News that he supports an extension of all the tax cuts during these hard economic times, a position that puts him squarely in line with his opponent. Likely the two would differ if there is an option to make all of the cuts permanent, but that remains unclear.

Still, Raese is trying to make the lame duck session an issue in the race, and his supporters warned in a local paper that deeply unpopular legislation to them like cap and trade and so-called "card check" legislation could also emerge.

Over in Delaware, though the Democrat, New Castle County Executive Chris Coons, holds a healthy lead in the polls, his tea party-backed opponent, Christine O'Donnell, is still in the race, and this campaign seasons has the feel of "anything can happen."

O'Donnell has made it clear she supports extending all of the Bush tax cuts, repeating a well-exercised GOP mantra that taxes should not be raised on anyone in a bad economy, no matter the impact on the deficit.

Coons takes a more nuanced approach, saying recently that he would not rule out bucking his party on whether or not to extend all of the Bush tax cuts, though he clearly prefers a middle-class-only approach favored by the president.

"With votes on ‘Don't ask, don't tell' and the Bush tax cuts already planned, Democrats need every vote in that session if we are to take on the challenges we face as a state and a nation," Coons warned his supporters in a recent mail.

"Our first priority is to reduce the tax burden on the middle class," Coons said on MSNBC, saying he opposes extending cuts for the wealthy, but then when asked if he would vote for a temporary extension of the cuts, he said he would consider it if it was the only thing offered.

And, indeed, there is a healthy coalition of moderates that supports a temporary extension, and the minority leader, Mitch McConnell of Kentucky, has said he would support a temporary extension if that is the only shot members get at dealing with the Bush tax cuts.

Senate Democrats could easily find themselves stymied by a GOP-led filibuster on all fronts during lame duck, particularly as it seems Reid could find himself moving farther away from a 60-vote majority, the number of votes needed to break a filibuster. 

A number of Democrats have, over this session, tried to find a way to eliminate the gridlock-inducing procedure, but Kaufman, a long time top aide to then-Sen. Joe Biden, D-Del., in his final floor speech, had a different message. The unassuming appointee said that despite all of the bitter partisanship of late, the filibuster should remain to protect the minority, adding, "I continue to have faith that out of the debates of the Senate, the fights we're having now, out of the frustrations of some of the intransigence of others, we will eventually find our way toward the next great compromise we need to solve so many of our problems, compromises that will keep America great."