Greene County, PA (though this seems to be the only county of its kind in PA, due to the closed primary there restricting turnout and its 1828-2000 era Democratic affiliation [sole exceptions: Smith, McGovern] boosting it)
Trumbull County, Ohio (many other such counties in Ohio)
Reynolds County, Missouri (a smattering of other such counties exist in Missouri)
Vigo County, Indiana (many other such counties in Indiana)
…all had more Hillary votes in the first half of 2008 than in November 2016, sometimes far more.
Why did Clinton lose in 2016? Because she couldn’t win anywhere near all Her 2008 voters. Let’s not even talk about the Obama coalition (which she couldn’t win in its entirety; see the vote in Detroit and the Black belt), Clinton failed to win the 08 Clinton coalition.
Why hasn’t the Hillary 08/Trump 2016 voter in Ohio been examined anywhere near to the extent of his and her importance? Eastern Ohio is (mostly) not racist (though it’s always been protectionist); look at its vote in 1860 and 1964. Trumbull County went overwhelmingly for Lincoln. #NeverLincoln Monroe, OH [Democratic in every election from 1828 to 2008, exceptions in 1928, 1956, and 1972] and Greene, PA, though, are exceptional in both the length and strength of their Democratic affiliation, and were only kept Democratic by protectionism in the later 20th century, only to switch to the Republicans in the early 21st century when the Democrats slowly abandoned their late 20th century protectionist message.