Magellan Strategies has released a new poll showing former Maryland Gov. Bob Ehrlich, R, leading his Democratic successor, Gov. Martin O’Malley, 46 to 43 percent. A few key topline results:

T4. Do you have a favorable or unfavorable opinion of Bob Ehrlich?

Favorable ………………………………………………………………………….. 51% Unfavorable ……………………………………………………………………… 32% No Opinion ……………………………………………………………………….. 16% T5. Do you have a favorable or unfavorable opinion of Martin O’Malley? Favorable ………………………………………………………………………….. 41% Unfavorable ……………………………………………………………………… 45% No Opinion ……………………………………………………………………….. 13% T6. Do you approve or disapprove of the job Barack Obama is doing as President? Approve …………………………………………………………………………….. 48% Disapprove ……………………………………………………………………….. 43% No Opinion ………………………………………………………………………….. 9%

At the same time, Marylanders continue to prefer Democrats for Congress, 42 to 34 percent.The sample in this poll is heavily Democratic (58 percent), as you might expect in Maryland. But the crosstabs show that 25 percent of registered Democrats plan to vote for Ehrlich.

The race is especially important because an Ehrlich victory could deprive Democrats of total control when they go to re-map the state’s eight Congressional Districts next year. (Republicans would also have to pick up five state Senate seats to sustain vetoes.) There isn’t much ground for Dems to gain in Maryland — there are only two districts at the moment where Republicans are competitive — but if they control the entire process they could try to give a more Democratic lean to the Eastern Shore district currently held by Rep. Frank Kratovil, D.