Anne Arundel County Maryland

[Benj]

Fact Montgomery County Maryland is now a 70 plus Democratic county, with 1 million residents no less, is quite remarkable when you consider it was still a toss up county in the 1980s.  

Reagan won it with 50 percent in 1984, and Bush I even managed 48 percent in 1992.  Even in past decade, seems all of the DC Maryland suburbs have moved about 10 percent points more D than they were in 2000.

1988, not 1992. Considering MontCo voted for Dukakis... Hardly a swing county.

Anyway, suburbs are growing in SW Anne Arundel. Even in the older suburban areas, swingy whites voters are being replaced by solidly Democratic blacks expanding outward from PG County. Annapolis itself has also become much more liberal and significantly more minority of late, partly because young members of the military are heavily minority and lean Democratic these days for the first time in a very long time. The traditionally super-Republican areas in NE Anne Arundel have also weakened a bit, down from 80+% Republican in the heyday to more like 60-65% Republican now.

[Benj]

It's mostly because of the military. Remember that the US Naval Academy is in Anne Arundel County. NE Anne Arundel County has a TON of military officers and retired military officers living in places like Lake Shore and Cape St. Clair. While the rank-and-file of the military has become more Democratic of late, the military leadership, especially retired ones, are still super Republican. The Navy (most of the Anne Arundel military presence) is also considerably more Republican than the Army, though less so than the Air Force and the Marines. The officer precincts are still incredibly strongly Republican.

Anne Arundel has not historically been a DC suburb; only the very fringe west of the county has had anyone commuting to DC until the past ten years or so. Much larger, especially in the past, are the suburbs of Baltimore in the north of the county, which are also quite Republican (Glen Burnie, Linlithicum Heights, etc.). Baltimore suburbs vote like they're in the South because to an extent they are.

Annapolis itself is only a small portion of the county, most of which is dominated by Baltimore suburbs and retired naval officers, plus increasingly DC suburban sprawl. The city itself is quite Democratic, but it's historically been outvoted by the Republican-leaning constituencies that have dominated the county in the past. That seems to be changing now with the growing DC suburban presence (including a lot more minorities), though, and I would not be surprised at all if Anne Arundel County voted for a Democrat for President in 2016.