The trend of suburban areas moving toward Democrats and rural areas moving toward the GOP has been going on for about the last two decades.
No it has not been going on for that long. A large extent of this happened only in 2016.
Los Angeles, Austin, San Antonio, Houston, Dallas, Chicago, Philadelphia, Pittsburgh, Detroit; the suburbs of each of these large cities all trended Republican in 2012.
One election with a relatively slight R trend after decades of Trending D(atleast since 92) doesn't prove much especially when Mitt Romney was an awful candidate for WWC areas like Lackawanna and Mahoning. He actually did worse than John Mccain.
