Yet it seems he may have an uphill battle in trying to secure a sixth.
"It is increasingly clear to both independent analysts and Democratic leaders that Dodd is just too badly damaged to have a decent shot at getting re-elected, almost regardless of who wins the Republican nomination," writes Jennifer Duffy, a Senate race analyst at the Cook Political Report, which is now predicting a Dodd loss.
For much of the past year, Dodd, who heads the Senate Banking Committee, was the subject of voter outrage for his role in the payment of bonuses to executives at AIG, the troubled firm that received a massive federal bailout.
Dodd's close connections to leading bankers are coming back to haunt him. One such connection is to former Bear Stearns director Edward Downe Jr., who once shared a condo with Dodd. After Downe's conviction for insider trading, Dodd leaned on President Clinton to pardon Downe at the end of his presidency.
Dodd's reputation also took a hit amid allegations that insurance giant Countrywide gave him "VIP" treatment in refinancing his home.
Poll numbers, Duffy of the Cook Political Report writes, suggest Dodd "is about as unelectable as unindicted incumbents get."
A poll past last month conducted by Quinnipiac University Poll showed 54 percent of voters disapproving of Dodd's performance as Senator.
Dodd is getting an assist today from Vice President Joe Biden, who is visiting Connecticut to highlight examples of federal funding in creating local jobs, such as the construction of a new fire station in East Hartford. He is also stopping by a fundraiser for Dodd, though the senator himself stayed behind in Washington for possible votes.