Washington (CNN) - Democrats apparently have one less thing to worry about as they try to keep control of the Senate in 2014: Dick Durbin isn't retiring.
A source familiar with the Senate majority whip's thinking confirms to CNN that Durbin next year will seek a fourth term in office. There was recent speculation that the Illinois Democrat, 68, would not run for re-election in 2014.
Durbin won 68% of the vote in his 2008 re-election victory against a little-known GOP opponent.
The news that Durbin will run for re-election, which was first reported over the weekend by the Chicago Tribune and WGN, should allay concerns by national Democrats, especially following last week's announcement by Sen. Carl Levin of Michigan that he will retire at the end of 2014, rather than make a bid for re-election. Levin became the fourth Democratic senator to announce that he'll step down at the end of next year, joining Jay Rockefeller of West Virginia, Tom Harkin of Iowa, Frank Lautenberg of New Jersey.
On the Republican side, Senators Saxby Chambliss of Georgia and Mike Johanns of Nebraska also decided against a run.
The Democrats currently hold 55 seats in the Senate (including two independents who caucus with the party) to the GOP's 45 seats. But at this point, they'll be defending 21 of the 35 Senate seats up for election in 2014.
With Durbin now running for re-election, retirement speculation on the Democratic side now is solely focused on Sen. Tim Johnson of South Dakota.