The Massachusetts Republican is looking unbeatable in his 2012 reelection bid, according to a Democratic Senatorial Campaign Committee (DSCC) poll obtained by Salon's Steve Kornacki:

But the DSCC received some bad news this week when a poll it commissioned found that Brown's popularity is soaring. The survey, which has been seen by at least one D.C. insider and was detailed for Salon, measured Brown's approval rating at 73 percent -- easily surpassing the scores for Barack Obama and the state's two top Democrats,  Gov. Deval Patrick and Sen. John Kerry. It also found him running over the magic 50 percent mark against every potential Democratic challenger, and crushing the strongest perceived Democrats (Reps. Michael Capuano and Ed Markey and former Rep. Marty Meehan) by double-digit margins. The results only grew closer when respondents were primed with negative information about Brown.

This is not encouraging news for any of those Democrats thinking about challenging Brown. Which also means that the leaking of this poll isn't going to help the DSCC field a strong candidate to win back Massachusetts, a heavily Democratic state that the party lost so epically when Brown came from behind to defeat Martha Coakley in January 2010.