Democrats fattened their majority control of the Senate on Tuesday, but by Thursday it was still not clear if they would have the 60 votes required to block any filibuster attempt. Three races were still too close to call. Those were in Alaska, Georgia, Oregon and Minnesota.

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Recounts and runoff elections could extend some of those contests.

It was clear, however, that Democrats had ousted Republican Sens. Elizabeth Dole of North Carolina and John Sununu of New Hampshire and captured seats held by retiring GOP senators in Virginia, New Mexico and Colorado.

Even without the undetermined contests, Democrats increased their majority to at least 56 seats in the 100-member Senate.

But Republicans stopped a complete rout, holding the Kentucky seat of Senate Minority Leader Mitch McConnell and a Mississippi seat once held by Trent Lott -- two top Democratic targets.

Here's a snapshot of contested U.S. Senate races:

Minnesota: Coleman vs. Franken Face Recount

A slugfest for nearly two years, Minnesota's U.S. Senate race headed into a new round Wednesday as the campaigns girded for an automatic statewide recount to determine if Republican Sen. Norm Coleman's slim lead over Democratic challenger Al Franken would stand.

Coleman declared himself the winner of Tuesday's election but Franken said he would let the recount play out, hoping it would erase the incumbent's 475-vote lead out of nearly 2.9 million ballots. State officials said the recount wouldn't start until mid-November and would likely take weeks.

Alaska: Sen. Ted Stevens vs. Mark Begich

Alaska U.S. Sen. Ted Stevens' re-election bid remains on thin ice.

Stevens is ahead, but only about 3,500 votes separate the Republican from Democratic challenger Mark Begich.

Stevens' political future is now dependent on roughly 60,000 absentee ballots and 9,000 early votes and questioned ballots. Those votes won't be counted for days.

Last week Stevens was convicted of seven felonies for failing to disclose more than $250,000 in gifts and services from an oil company executive.

He stands to be the first convicted felon re-elected to the Senate. But Stevens' colleagues could also expel him and end the longest run by a Republican in the history of the body.

Georgia: Chambliss Leads Jim Martin

The race between Republican incumbent Sen. Saxby Chambliss and Democrat Jim Martin appears to be headed to a runoff. The latest vote tallies from the AP show Chambliss just shy of the 50 percent plus one vote needed.

Chambliss acknowledged the vote totals could still change but "our position is we're in a runoff."

Said Martin, "The runoff race begins right now."

Oregon: Merkley Defeats Smith

The Democratic challenger in Oregon's Senate race, Jeff Merkley, has defeated Republican Sen. Gordon Smith.

It was one of the last Senate races to be decided. A flood of votes Oregonians delivered on Election Day kept election workers tallying ballots for two days.

Merkley, speaker of the House in Oregon, planned an appearance Thursday morning to claim victory, and Smith planned a press conference in the afternoon.

Smith, the two-term senator, had run TV ads touting his work with Barack Obama and other prominent Democrats in an effort to portray himself as a political moderate.

But Merkley countered with a TV ad featuring Obama urging Oregonians to vote for Merkley.

Kentucky: McConnell Holds Off Lunsford

U.S. Sen. Mitch McConnell of Kentucky survived a major election challenge, outpolling Democratic contender Bruce Lunsford.

McConnell, the Senate minority leader, on Tuesday overcame a strong bid by Lunsford, a Louisville millionaire who poured substantial money into his campaign.

McConnell, the Senate's top Republican, is the fiercest congressional critic of the military junta ruling Myanmar. He and President George W. Bush's wife, Laura, have worked closely together in recent years to increase international pressure against the ruling generals.

For many years, McConnell has used his influence to keep Myanmar high on the agendas of the State Department and White House, despite a lack of attention or interest from the American public.

North Carolina: Hagan Unseats Dole

North Carolina Democrat Kay Hagan has knocked Elizabeth Dole -- one of the biggest names in the Republican Party -- out of the U.S. Senate after just one term in office.

Hagan was a little-known state senator from Greensboro when she entered the race to unseat Dole one year ago. But Democrats eager to reach a filibuster-proof majority in the Senate rushed to her aid with millions of dollars in advertising that tarnished Dole's name and left voters with the impression she was ineffective and out of touch.

The loss for Dole likely ends a political career that included two postings in Republican cabinets and a run for the White House.

Warner Takes Virginia

Democrat Mark Warner has defeated his fellow ex-governor Jim Gilmore for a Republican-held Senate seat in Virginia. The win gives Democrats control of both of Virginia's Senate seats for the first time since 1970.

Tuesday's matchup pitted governors with sharply different styles and records. Warner held huge leads in polls throughout the race and Gilmore never gained traction.

Warner will succeed John Warner, who is retiring after a 30-year Senate career. The two are not related.

New Hampshire: Shaheen Upsets Sununu

Democrat Jeanne Shaheen has defeated Republican Sen. John Sununu to become the first woman elected to the U.S. Senate from New Hampshire.

Shaheen, who also was the first woman elected governor of New Hampshire, will be its first Democratic senator in more than 30 years.

She defeated Sununu in a bitter rematch in which the candidates stayed the same, but nearly everything else changed.

After losing to Sununu in 2002, Shaheen benefited this time from demographic trends favoring Democrats and her efforts to link Sununu to the unpopular Bush administration.

Sununu's loss -- his first ever -- hands Democrats hoping for a filibuster-proof majority in the Senate a seat they have been salivating over for more than a year.