Elizabeth Warren currently holds a five point lead over incumbent Republican Sen. Scott Brown in the Massachusetts Senate race, according to PPP.

PPP’s newest Massachusetts poll finds Elizabeth Warren leading Scott Brown 46-41.

Brown is not proving to be an overwhelmingly popular Senator. 45% of voters approve of the job he’s doing to 42% who disapprove. That’s actually up a little bit from a 44/45 spread on our last poll in September. Republicans love him, giving him an 80/7 approval spread. But his appeal to Democrats and independents is not what it once was. At the end of his first year in office Brown was nearly running even with Democrats, with 35% approving of him to 41% who disapproved. Now he’s at 23/63 across party lines. And although he remains popular with independents at 53/34, it’s not the 61/25 rating he enjoyed with them at the end of 2010.

While five points is a relatively small lead, trailing by any amount this far out from the election is normally considered to be bad news for an incumbent.

Brown is still relatively well liked, but I don’t think that will last long. In Massachusetts over half the state is Democratic or Democratic leaning. Once the campaign gets really underway, simply tying Brown to his own party should push up his negatives. Brown has a lot of potential downside going forward but not a lot of potential upside.