Democrats have a 51-49 majority in the Senate that depends upon the support of independents Joe Lieberman and Bernie Sanders. However, Lieberman supports John McCain for President, which suggests the Connecticut Senator may vote with Republicans in a new Congress. Therefore, if Democrats want to increase their majority to 60, so that Barack Obama's agenda would not be held hostage by Republican filibusters, they will have to add 10 new Senators. A big task, but not impossible if Obama scores a big win over McCain.