I don't think the title is true. The final tally was Clinton +149, but the Election Night tally was Trump +388. That decreases Trump's margin by only 537 votes, not 22,000.
Dave wasserman on twitter say otherwise.
Ah, I read it incorrectly. The dump was statewide, not in Lorain... which makes it less noteworthy in general. Losing 20,000 is ~4% of Trump's lead in Ohio.
If you compare Wasserman's spreadsheet to the results for CNN or the NY Times (these are the same, so they are probably from AP), there is a 56K:34K increase statewide. Which is about 1.8% of the total vote.
Ohio lets voters vote provisionally out of precinct. These voters tend to be concentrated in urban areas and are more likely to be Democratic. If you live on a farm in western Ohio, you are unlikely to go to the wrong polling place, 10 miles away when your polling place is 4 miles away and you have voted there for the past 50 years.
There were about 3600 votes added in Lorain County, which went from a 388-vote Trump margin to a 131-vote Clinton margin.
Obama carried the county by 26,000 votes in 2008, 200 times the size of Clinton's margin.
Of the drop in Clinton support, it appears about 1/3 went to Trump, 1/3 went to others, and 1/3 stayed home.
