The Democratic firm Public Policy Polling takes the temperature in the Massachusetts Senate race, and finds Democrat Elizabeth Warren gaining momentum:

Things have been going Elizabeth Warren's way in the Massachusetts Senate race over the last month. She's gained 7 points and now leads Scott Brown 48-46 after trailing him by a 49-44 margin on our last poll.

Warren's gaining because Democratic voters are coming back into the fold. Last month she led only 73-20 with Democrats. Now she's up 81-13. That explains basically the entire difference between the two polls. There are plenty of Democrats who like Scott Brown- 29% approve of him- but fewer are now willing to vote for him. That's probably because of another finding on our poll- 53% of voters want Democrats to have control of the Senate compared to only 36% who want Republicans in charge. More and more Democrats who may like Brown are shifting to Warren because they don't like the prospect of a GOP controlled Senate.