The poll indicates that former US representative Joseph P. Kennedy II would pose the strongest challenge to the Republican senator. In a hypothetical head-to-head race, Kennedy would receive 40 percent of the vote to Brown’s 45 percent. Kennedy, however, has indicated to leading Democrats that he has no interest in challenging Brown.
Brown would more easily defeat Patrick, by 52 percent to 37 percent; Victoria Reggie Kennedy, by 52 percent to 30 percent; and Lieutenant Governor Timothy P. Murray by 51 to 23 percent. Though all three have been mentioned as potential candidates, Patrick, Murray, and Kennedy have said that they will not challenge Brown in 2012.
Brown would also beat US Representative Michael E. Capuano of Somerville, 52 percent to 26 percent; Representative Edward J. Markey of Malden, 53 percent to 26 percent; and Mayor Setti Warren of Newton, 52 percent to 9 percent.
http://www.boston.com/news/local/massachusetts/articles/2011/04/07/new_poll_shows_brown_faring_well_against_possible_challengers/
http://www.suffolk.edu/offices/46306.html
No Republican has lead in a MA Senate race by 43 points in any poll probably since the days of Saltonstall, unless thats a misprint.