FACTBOX: Senate races going Democrats' way

(Reuters) - With the economic crisis hurting Republicans in the elections on Tuesday, Democrats were building strength in the Senate but were unlikely to attain the 60-seat super majority they sought in the 100-seat U.S. Senate.

Holding 60 seats would have given Democrats the muscle to pass legislation in spite of Republican procedural hurdles. But a nine-seat gain appeared to be out of reach, according to senior Democratic aides in the Senate.

Overall, 35 Senate seats were up for election -- 23 held by Republicans and 12 by Democrats.

On the other side of the U.S. Capitol, Democrats were expected to pick up around 25 seats in the House of Representatives, which they now control 235-199. All the 435 House seats are up for election

Here's a look at projected results in key Senate races as well as a number of unresolved contests:

ELECTION RESULTS:

* Democratic Rep. Tom Udall won a U.S. Senate seat in New Mexico, replacing Republican Sen. Pete Domenici, who retired.

* Another Democrat, Rep. Mark Udall, who is Tom's cousin, was projected to win the Colorado Senate seat to replace Republican Wayne Allard, who retired.

* Democrat Mark Warner, a popular ex-governor, won in Virginia, capturing a Senate seat held by Republican John Warner, who also is retiring.

* Republicans lost another Senate seat in North Carolina, where Elizabeth Dole was beaten by Democratic state senator Kay Hagan.

* Former New Hampshire Gov. Jeanne Shaheen added to the Democrats' big night by beating incumbent Sen. John Sununu, according to media projections.

* But Senate Republican Leader Mitch McConnell of Kentucky won a fifth term, after a tough challenge from Democratic businessman Bruce Lunsford.

* Moderate Republican incumbent Susan Collins won re-election in Maine, helping kill Democratic chances for obtaining a 60-vote supermajority.

* Republican Sen. Saxby Chambliss of Georgia also fended off a challenge from former state Sen. Jim Martin, a Democrat. In Mississippi, Sen. Roger Wicker, a Republican, also held onto his seat.

* Sen. Mary Landrieu of Louisiana, the only Senate Democrat in a competitive race for re-election, beat Republican state Treasurer John Kennedy.

* Democratic Rep. John Murtha survived a close call, winning reelection despite recent controversial remarks in which he described western Pennsylvania, which he represents, as a "racist area." Murtha is the powerful chairman of a House panel that oversees U.S. defense spending.