Starting with the 1992 presidential election, political alignments shifted enough to create a “blue wall” due to increasing Democratic voting strength in affluent suburbs in larger metropolitan areas in the Pacific Northwest, the Northeast, New England and Chicago/Detroit in the Midwest.
This “blue wall” gave Democrats a substantial head start between 1992 and 2012. While Donald Trump shattered the “blue wall” in 2016, a less-noticed countervailing trend was Democrats becoming more competitive in Southern/Western suburbs of cities like Atlanta, Dallas, Houston and Phoenix. Whether this realignment occurs in Congressional races this year determines who controls the House.
– John Couvillon, President and Founder of JMC Analytics and Polling