All watching expect Senator Obama to sweep D.C., Virginia and Maryland today but Martin Frost writing at the Politico suggests that because of Maryland’s history he might win the state but not get the sweep he is hoping for.

Though now considered a heavily Democratic state and a generally liberal enclave, Maryland has a long — but little-known — history of racial division that may cut into Obama’s margin. It is not by accident that the Mason-Dixon Line (separating the North and the South) is the northern boundary of Maryland.

Maryland has a large black population, which would seem to favor Obama. The black vote could be even larger than normal because of a contested congressional primary in Prince George’s County and a sliver of neighboring Montgomery County. In the 4th District, community activist Donna Edwards is challenging Rep. Albert Wynn from the left; both candidates are black, and the primary will be held the same day as the presidential voting.

However, for a variety of reasons, the dynamics of the Maryland presidential primary may boost Clinton’s support. White voters on the Eastern Shore and in the western part of the state are very conservative and may be reluctant to vote for a black candidate.

The liberal bastion of Montgomery County in the D.C. suburbs contains many former officials from Bill Clinton’s administration, and Hillary Clinton’s share of the women’s vote could be very strong there.

Also, largely ignored is the fact that Maryland has a sizable Jewish population. When I was a young man in the 1960s, my Maryland relatives used to kid me about the fact that Baltimore had a larger Jewish population than the entire state of Texas, where I grew up. Texas has probably caught up by now, but the Jewish population of Maryland is still very large and very politically active.

There is a lot more in the article so check it out!