Democrats face an uphill fight as they look to recapture the Senate seat formerly held by Ted Kennedy in Massachusetts.

In the most recent Suffolk University/7News poll, Republican Sen. Scott Brown led all potential Democratic opponents by at least 15 points with the exception of former Rep. Joe Kennedy, who only trailed by five.

But Kennedy has flatly ruled out a Senate run, joking with reporters a few weeks ago that he was "feeling ill all of a sudden" when they asked him about challenging Brown.

Gov. Deval Patrick has the next best numbers against the Republican incumbent (he trails Brown 52-37), according to the poll, but he too has ruled out a possible run as he prepares to help President Obama's re-election efforts in 2012.

Ted Kennedy's widow, Vicki, trailed 52-30, but she told the Boston Globe in January that she will not pursue her late husband's former seat, which effectively freed potential challengers to begin positioning themselves for 2012.

A flurry of names has been floated around by the local and national press, including Rep. Michael Capuano, Lt. Gov. Tim Murray, Harvard professor Elizabeth Warren, Newton Mayor Setti Warren, Rep. Ed Markey, and City Year co-founder Alan Khazei.

But in polls none have fared well against Brown, who continues to boast high favorability ratings. More than half -- 55 percent -- of Bay State voters said the junior senator deserves to be re-elected, and 56 percent said they agreed that Brown has maintained his pledge to be an independent voice in Washington.

"Brown is beating all expectations," said David Paleologos, director of the Suffolk University Political Research Center, in a news release. "His popularity hasn't diminished as most expected, and at this point in time he's going to be tough to beat."