To add to PM_ME_UR_OBSIDIAN's comment; maybe everywhere apart from the coastal cities, but definitely in key states like Florida, Pensilvaina and north Carolina large parts of the white working class electorate switched from voting for Obama twice to voting for Trump. Both Trump and Obama ran as 'change' candidates or had large doses of 'anti system' messages in their campaigns. People who are dissatisfied are much more likely to vote for anti system/change candidates and I think that Trump and Obama engaged with voters on a number of economic issues specific to a specific areas of the country and constituencies.

People take and see what appeals to them and kind of see other things less clearly, he promised to alter trade agreements 'bring back jobs' to communities that have seen jobs with decent pay become less common.

Clinton (even though she did have policies that maybe would've addressed some of these concerns) ran as a 'pro system' candidate and this played well with people who are doing ok (mostly) but not with people who aren't or fear for the future.