Senate races

Struggling Democrats managed to keep control of the U.S. Senate after claiming victories in key states that have been seriously challenged by Republican opponents in this year's midterm elections.

U.S. mid-term elections

ABC and CNN, citing exit polls, projected that Republicans failed to capture the 10 seats needed to overturn Democrats' majority in the Senate.

Republicans' failure in races in West Virginia and California, two of a dozen toss-up states that were seen up for grabs, made it impossible for Republicans to gain majority in the Senate.

Democrat Joe Manchin, governor of West Virginia, won the Senate race in the coal-rich state, beating back Republican rival John Raese, a local businessman.

In California, three-term Democratic Senator Barbara Boxer won a tight race with Republican candidate Carly Fiorina, former chief executive of computer giant Hewlett-Packard.

Still, Republicans made some gains in states like Pennsylvania, Wisconsin, Arkansas, North Dakota and Indiana, ensuring them a louder voice in the new Senate.

The changing balance of power in the upper house means that Democrats may no longer be able to use their old tactics -- unifying their own members and picking off two or three Republican moderates -- to push a bill through the Senate. Instead, Democrats may have to seek bipartisan support to fend off a filibuster.

Many of the Tea Party backed candidates have proved to be highly competitive in Senate races.

In a three-way races, Republican candidate Marco Rubio, backed by the Tea Party movement, won the Senate race in Florida, beating the state's Governor Charlie Crist, who ran as an independent, and Democratic candidate Kendrick Meek.

Another Tea Party favorite Rand Paul, son of former Presidential candidate Ron Paul, won over Democrat Jack Conway in Kentucky Senate race.

But the Tea Party star Christine O'Donnell lost her bid for the former Senate seat of Vice President Joe Biden in Delaware, sending her Democratic rival Chris Coons to the Senate.