Maryland Population Shifts by State Senate District

So yeah, lately in my few spare moments I’ve been working on the perfect Maryland legislative redistricting map. Before I release that though, I want to talk a little about the thought process that goes into such a map. Today’s diary will show how the population in Maryland has shifted over the past decade, and what this will mean for redistricting in my beloved home state.

To start, I made a map using Census 2010 colors, that shows how the state’s districts have grown over the past decade.

From this map we can make several conclusions:

– Given that the state growth rate was around 9%, it makes sense that most districts would be in the 5-15% range.

– Growth in traditionally high-growth exurbs of Baltimore (Carroll, Harford, northern Baltimore County) slowed to the state average this decade.

– Many of Baltimore’s inner suburbs stagnated (although this is an improvement for Essex/Dundalk, which had been losing population for decades)

– 5 of Baltimore City’s 6 districts lost significant population, guaranteeing the loss of a State Senate district. The one that actually did post a modest gain, District 46, is the one most likely to be abolished given that it’s the only non-majority black district in Baltimore City.

– The only district to lose population outside of Baltimore City was majority-black District 24 in Prince George’s County. Every district in MD that lost population over the past decade was majority-black.

This might be worth exploring in a later diary, but the correlation coefficient between %black and %growth was -.54, while for whites it was .42, Asians .39, and Hispanics .05

– The highest growth area of the state by far is the I-270 corridor in Frederick/Montgomery Counties. District 15 gained an amazing 28%, while District 3 gained 25%.

– Other areas growing significantly faster than the state average include:

     – the western Baltimore suburbs (9 and 11)

     – Gaithersburg/Rockville (17)

     – Southern Maryland (27, 28, and 29)

     – Outer Prince George’s County (21 and 23)

     – the Upper Eastern Shore (36) – mostly from high growth around Elkton and Kent Island

– Although growth stagnated in the inner DC suburbs, the balance of power in the state continues to shift towards DC.

Redistricting Implications

Growth isn’t everything. Another important consideration is the extent to which current districts are over or under population. Under the law, districts must be within 5% deviation of the mean population. The following map shows what districts are over, under, or acceptable.

From this map, one can see that inner Baltimore and DC suburbs districts will need to expand, while the outer suburban and rural districts will need to contract.

Side Note about Deviation

It’s important to note that a lot of the underpopulated districts started out with fewer people in 2000. Here’s a map showing which districts were drawn to be over and under the median (but within 5%) in 2000.

As you can see, the Democratic Party has used acceptable deviation as way to slightly maximize the influence of its most loyal counties – Prince George’s, Montgomery, and Baltimore City. Expect to see deviation put to good use in my map, as well as in the map that eventually gets drawn.

Conclusion

So yeah, that’s it. I hope this gets a few people talking and/or thinking. Before I release my perfect legislative map, I’m thinking about writing a diary on the history of Maryland legislative redistricting, so be on the lookout for that as well.