I wanted to ask about the story of three Denver metro area suburban counties. In the 2004 Presidential election, John Kerry narrowly won Adams County while narrowly losing Arapahoe and Jefferson counties. Adams remained moderately more Democratic than the two other counties in the 2008 and 2012 Presidential elections. By 2016 Arapahoe was more Democratic than Adams and Adams was the only county where Trump increased the absolute Republican percentage from 2012. In last year's Presidential election, Jefferson also was more Democratic than Adams with Arapahoe pulling far ahead. Is there a reason Adams County has gone from being the most Democratic county to the least of the Denver metro counties especially since Adams has been a largely Democratic county since 1960? Is Adams County more working-class? It would seem that Adams's comparatively large Latino population would encourage it to be more Democratic.
Arapahoe County has the largest black population in the state - higher than in Denver.
Historically, the black population in Denver has been in east Denver. As it has become more middle class the black population has continued to move east into Aurora.
Arapahoe is narrower than Adams, 12 miles vs. 18 miles, but even narrower when you consider the location of Denver. Arapahoe County used to include what is now Arapahoe, Adams, most of Denver, and stretched east to Kansas. Denver was the county seat.
When the City and County of Denver was created, the perception of the remainder of the county would be agricultural areas to the south and north of the city. Since they were physically separated, they were placed in different counties. The area to the east was (and is) largely empty. Eventually, Washington and Yuma were created in the very east end.
Littleton, the county seat of Arapahoe County is in the extreme southwestern corner of the county. Brighton, the county seat of Adams County is on the northern border. While Brighton is northeast of Denver, it is still in the western 1/6th of the county.
The area of Arapahoe County south of Denver is only about 6 miles wide, and Denver has annexed areas that are suburban. Denver has a more reliable water supply, and would make deals with developers to annex their land in exchange for water.
The area south of Denver was filled up decades ago. If you are building new houses they are going to be in Douglas or southern Jefferson. Houses in Englewood are quite modest, and largely pre-WWII.
The area east of Denver is in Aurora. Aurora developed their own water sources, and so can serve new developers and there is unlimited land. East of Denver is less favored because it is further from the Mountains. There is also good access to the airport. Blue collar workers from the old airport (Stapleton) might reasonably move out to Aurora. Aurora was traditionally on the Arapahoe-Adams line (on E Colfax), but most of the growth has been on the Arapahoe side, and the city now reaches Douglas County. It can't really develop to the north because of the airport, but might have some development to the east along I-70. These areas might be somewhat disfavored for residential development since they may be in the approach and departure paths for the airport.
The historic industrial area in Denver was along the Platte northwest from downtown. This extended into Adams. The only refinery is in Commerce City. As the Platte Valley widened out in Adams it was more suitable for irrigated agriculture. South of Denver is higher, so the weather is literally cooler. Pollution flows downhill, so the brown cloud would flow into Adams. The Platte Valley is shallower to the south, and the wind can disperse pollution better.
There are areas literally on the northern border of Denver that were never annexed. They were not desirable additions to Denver, which would prefer residents who paid more in taxes than they required in services.
Adams has good access to the airport. Large tracts of land are amenable to manufacturing. They can build large structures of precast concrete with large production space, and large areas for storing raw materials and finished product. Outside there is space for loading docks and parking for workers.
Adams had less population to start with, and more area to expand. While the workers won't be well off, they will be in Adams County rather than Douglas County.
Jefferson County is somewhat limited. Expansion into the foothills is expensive and limits growth except for the extreme south and north ends. The north end is mostly filled up, and the south end is limited as the eastern boundary follows the Platte River into the mountains. A major employer in Jefferson County is the Federal Center. Many agencies have their regional headquarters in Denver. Government workers will vote to the left of the private sector.
