The Senate map for 2012 is just inherently awful for Democrats. They have to defend incumbents in 23 states, while the Republicans only need to defend 10. Even if there is a relatively strong national Democratic turnout in 2012, the party will likely still have a net loss of Senate seats.

With that factored in, though, the prospects for the Democrats at least narrowly holding on to the chamber have been improving.

New polling in three potential competitive Senate races, Massachusetts, Ohio, and Michigan, has all been relatively positive for Democrats.

Massachusetts – A new WBUR poll has Democrat Elizabeth Warren with a three point lead over incumbent Republican Scott Brown, Warren 46 percent to Brown 43 percent. For an incumbent to be trailing (and below 50 percent) this early is a very bad sign. Massachusetts is one of the Democrats’ only pickup opportunities this cycle and will likely be needed to offset almost assured loses elsewhere.

Michigan – Incumbent Democrat Debbie Stabenow now has a 14 point lead over potential Republican rival Pete Hoekstra. This is a huge improvement from earlier in the year; also important, Stabenow is polling at least 50 percent in potential matchups. From PPP:

Debbie Stabenow’s taken her biggest lead yet in 4 polls of the Michigan Senate race PPP has conducted dating back to December of 2010. She now leads Pete Hoekstra by 14 points, 51-37, and has an even wider 17 point advantage over Clark Durant at 50-33. In 3 previous polls Stabenow led Hoekstra by an average of just 7 points and on the most recent one, in July, her lead was 9.

What’s interesting is that Stabenow’s approval numbers have barely budged at all over the last 6 months. Over the summer we found her at 46/40, and now she’s at 47/41.  But Hoekstra’s numbers have taken a turn for the worst.  In July his favorability was narrowly positive at 31/30. Now he’s dropped a net 11 points to a -10 spread at 28/38. There hasn’t been a big shift in his numbers with Democrats or Republicans but with independents his numbers have flipped from +10 (33/23) to -10 (29/39).

Ohio – Ohio incumbent Democrat Sherrod Brown hasn’t seen his numbers improving, but he is still holding a steady, significant lead in polling. According to Quinnipiac polling Brown leads Republican Josh Mandel 48 percent to 35 percent. This roughly 12 point lead is basically unchanged since last summer. Brown’s favorable numbers are also steady, 41 percent favorable to 46 percent unfavorable.

There was a time earlier last year when it looked like Democrats could be heading towards very big losses in the Senate this year. A net loss of half a dozen or more seats seemed possible. With both the economy and President Obama’s polling showing signs of modest but steady improvement in the past few months, there are now signs the Democrats could narrowly hold on to the Senate in spite of how unfavorable the Senate map is. It is still very early in the season, but things are looking less gloomy for Senate Democrats.