Democrat Jon Tester, a Montana state senator, has defeated incumbent Republican Sen. Conrad Burns, putting the Democrats just one state away from a majority in the U.S. Senate.

Preliminary results put Tester ahead of Burns by about 2,400 votes, less than 1 percent of votes cast in the state.

With Tester's win, Democrats will reclaim five Senate seats from Republicans since Tuesday's election.

Now, all eyes are on Virginia, where Democratic challenger Jim Webb is narrowly leading incumbent Sen. George Allen. Webb declared victory early Wednesday, but Allen has yet to concede, signaling he may fight the results with a recount.

A statewide recount is allowed if two candidates' vote counts are less than 1 percent apart.

At latest tally, Allen was leading the incumbent Republican by less than one-half percent.

Democratic Missouri state Auditor Claire McCaskill is projected to defeat incumbent Sen. Jim Talent as Democrats are clinging to hopes to capture control of the U.S. Senate from Republicans.

McCaskill unseated Talent, who was elected to the Senate in 2002 after defeating then-Sen. Jean Carnahan, by a narrow 1-point margin.

So far, Democrats lead Republicans with 50 Senate seats for the Democrats and 49 for the GOP. The future of the Senate hinges on Virginia. Democrats have taken five seats back from Republican control, and need six to capture a 51-49 majority.

Democrats must win Virginia to win control; winning 50 seats is not enough, since Republican Vice President Richard Cheney would break Senate ties.

Democrats are holding on to Senate seats in Florida, West Virginia and Massachusetts, Republicans holding in Maine and Indiana and an independent, who is likely to vote along the same political lines as Democrats, in Vermont.

Democrats were dealt a blow in their efforts to win a Senate majority when Republican Bob Corker defeated Rep. Harold Ford Jr., Tenn., in Tennessee. Corker won by 3 percent.

In Pennsylvania, Democrat Robert Casey Jr. is projected to defeat long-time Republican incumbent Sen. Rick Santorum, the third-highest ranking U.S. Senator.

In Ohio, incumbent Republican Mike DeWine is projected to lose to Democratic challenger Sherrod Brown. That indicates a one-seat net gain for Democrats thus far.

Independent incumbent Joe Lieberman is projected to win in Connecticut by about a 10-point margin over Democrat candidate Ned Lamont. Lieberman, long-time Democrat, lost in the Connecticut Democratic primary, and is likely to vote with Democrats.

In Vermont, independent Bernard Sanders is likely to defeat Republican Richard Tarrant. Sanders will occupy the seat vacated by Sen. James Jeffers, also an independent. Sanders is expected by many pundits to vote much like his predecessor, who often aligned with Senate Democrats.

In Rhode Island, Republican incumbent Lincoln D. Chafee will likely be defeated by Democrat Sheldon Whitehouse, the third party switch of the night, according to proprietary exit polling data.