Much has been said about the long-term demographic challenges facing the Republican Party. Given how dismally Republicans fare with African-American voters—Mitt Romney and congressional Republicans garnered only 6 percent and 8 percent, respectively, in 2012, and this year congressional Republicans got 10 percent—it matters how the GOP does with other minority voters.
In 2012, Romney picked up 27 percent and congressional Republicans received 30 percent of the Latino vote. This year, House Republicans got 36 percent. This doesn't matter that much in the House, because of natural residential patterns and, to a lesser extent, gerrymandering. But it is a big deal in presidential matters and in some Senate election years more than others (the Latino vote will be much more critical in the 2016 class of Senate seats than it was in the 2014 grouping).
But considerably less is being said about a parallel problem that Democrats are facing. Although the national red-blue maps of the partisan makeup of the House, the governorships, and, somewhat less so, the Senate are misleading in that they equate population with land area, the maps do illustrate where Democrats are strong and where they are not (interesting factlet: Only 14 percent of the land area in the U.S. is represented by a Democrat in the House). Increasingly, Democratic strength is concentrated primarily in urban areas and college towns, among minorities, and in narrow bands along the West Coast (but only the first 50 to 100 miles from the beaches) and the East Coast (but only from New York City northward). The South and the Border South, as well as small-town and rural America, are rapidly becoming no-fly zones for Democrats. Few Democrats represent small-town and rural areas, and the party is find it increasingly difficult to attract noncollege-educated white voters.