Maryland is traditionally considered a Southern or border state, but politically it most closely resembles the urbanized states of the Northeast. Most of its population is in the cities and suburbs of the central portion of the state; only about 17 percent is in the traditional rural areas to the west and east.
Like most Northeastern urban areas, Maryland usually favors the Democratic party. Traditionally the state had a large southern rural population which voted Democratic due to preferences rooted in the Civil War. Today its Democratic preference comes from a variety of sources, including a large African American population (about 30% of the state total), an active organized labor presence, many federal workers near Washington, DC, recent immigrants, and many wealthy suburbanites who hold liberal views on cultural issues. In most elections that disparate coalition is enough to outvote the rural voters (including many former Democrats)and more conservative suburban and exurban residents who vote Republican.
Maryland's current governor is Martin O'Malley, a Democrat elected in 2006 over one term Republican incumbent Robert Ehrlich by a 52-46% margin. Voting patterns in the 2002 and 2006 elections show that Ehrlich won the rural and exurban areas by wide margins, and lost Baltimore City and the Washington, DC suburbs by similar margins. The balance is struck in the Baltimore suburbs, the largest of which, Baltimore County (which does not include the city), was won by Ehrlich in 2002 by a wide margin (61-38%) but only barely in 2006 (51-48%), a dropoff that was also visible in suburban counties such as Howard and Anne Arundel and explains the differing statewide results. Other state-level officeholders are Lieutenant Governor Anthony Brown, who was elected jointly with O'Malley, Attorney General Doug Gansler, and Comptroller Peter Franchot. All are Democrats serving their first terms in their current offices.
The state legislature consists of a 141-member House of Delegates and a 47-member Senate. Party balance in the House is 104 Democrats to 37 Republicans; the Senate is 33 Democrats to 14 Republicans. Most districts are composed of one senator and three delegates; some Senate districts are split into two or three subdistricts that elect one or two delegates each. The current legislative map is here: http://www.mdp.state.md.us/msdc/Redist/legd02/leg02_md.htm
Democrats have large legislative majorities because of their dominance of Baltimore City and suburban Montgomery and Prince George's Counties near Washington, DC. Currently, every state legislator from those three jurisdictions is a Democrat, and those 65 delegates and 21 senators make up a near majority (46%) of the total legislature. Another third of the legislature represents the Baltimore suburbs (Baltimore, Carroll, Harford, Anne Arundel, and Howard Counties). Befitting its swing region status, suburban Baltimore's legislative delegation is closely balanced between the parties with 9 Democratic and 7 Republican senators, and 25 Democrats and 23 Republicans in the House. The three counties of Southern Maryland (Charles, Calvert, and St. Mary's), which is traditionally rural but is seeing Washington suburban growth, send a mostly Democratic delegation to Annapolis; all three of the area's resident senators and six of seven delegates are Democrats, although statewide races in the region are usually close. At opposite ends of the state, the four counties of Western Maryland and the ten of the Eastern Shore (the region located east of the Chesapeake Bay) are the two areas where Republicans dominate. Republicans hold all 7 Senate seats in those two regions and 14 of the 22 House seats, but combined those areas make up only 15% of the total legislature.
At the federal level, Maryland is similarly a Democratic-leaning state, with some exceptions. Maryland has elected US Senators of both parties throughout its history, though since 1987 they have all been Democrats. Barbara Mikulski and Ben Cardin are the current Senators. Its House delegation, which has had eight members since the 1960s, is currently 6 Democrats and 2 Republicans, but in the 1990s was evenly split between the parties. Redistricting in 2002 strengthened the Democrats' hand, as the Republican leaning Eastern Shore and western portion of the state make up the basis of one district each, with the remainder of the state sliced up into six districts in a way intended to maximize Democratic representation, in many cases at the expense of geographical compactness. Current congressional districts are shown here: http://www.mdp.state.md.us/redistrict/2002congressional_dist_sb805_may602.pdf
In presidential races, Maryland was a highly competitive state from the 1940s to the 1980s. From 1940 to 1988, Democratic presidential candidates carried it seven times and Republicans six times. Democrats have carried it by wide margins in all four presidential elections since 1992.
As of July 2008, Maryland has 3.23 million active registered voters. Of them, 1.81 million (56%) are Democrats and 902,000 (28%) are Republicans, with the remaining 16% unaffiliated or registered with other parties. Democratic registration advantages are strongest in Baltimore City, where 79% of voters are registered Democrats, and Prince George's County, where the figure is 77%; both of these jurisdictions are about two thirds African American in population, and black voters here as in most other places overwhelmingly support Democrats. The state's largest jurisdiction in terms of population is Montgomery County, which has 524,221 registered voters of whom 56% are Democrats and 23% Republicans. These figures are not far off from the state totals, but Montgomery's voting is significantly more Democratic than the statewide total due to the fact that many independent voters there vote for Democrats due to support for their issue stands; Montgomery County voted 62% for Baltimore Mayor Martin O'Malley for Governor and 68% for Democratic Congressman Ben Cardin for Senator in 2006 as they won by 52% and 55% statewide, and its 17% of the total statewide vote was more than that of any other county or city.
Elsewhere in the state, party registration does not always predict voting habits. In the Baltimore suburbs and rural areas, there are many voters who register Democratic for primaries for local and legislative office, but often vote Republican at the top of the ticket. Baltimore County has a Democratic edge of 59%-27% in registration terms, similar to Montgomery County, but has many more ticket splitters as in 2006 it was competitive atop the ticket, voting for Ehrlich for governor by 51-48 and Cardin for Senator by 52-47, making it the only jurisdiction in the state to split its vote in the two contests. Anne Arundel County, another large suburban Baltimore county, has a Democratic registration edge of 44-38% but conservative voting habits; it voted for Ehrlich in 2006 by 56-42 (a sharp drop from Ehrlich's 2002 margin of 65-34%) and for Republican Michael Steele, who served as Ehrlich's Lieutenant Governor, for Senator over Cardin by 54-44%. Currently only seven of the state's 24 jurisdictions have more registered Republicans than Democrats; they are the five counties along the northern border of the state from Garrett to Carroll Counties, and Queen Anne's and Talbot Counties on the Eastern Shore. Current county-by-county figures are here: http://www.elections.state.md.us/pdf/vrar/2008_07.pdf
Official state government website: http://www.maryland.gov/portal/server.pt?
Interactive maps of current congressional and legislative districts: http://redistricting.state.md.us/maryland/
State Board of Elections, containing election results dating to the 1980s and detailed voter registration figures: http://www.elections.state.md.us/index.html
Maryland Manual Online, containing detailed information about state and local officeholders, as well as general information about the state and its government: http://www.msa.md.gov/msa/mdmanual/html/mmtoc.html