That's interesting; Gore didn't carry the old South Milwaukee district in 2000.
Maybe Reagan's attitude toward Poland and other Soviet controlled nations hurt him in the district (a lot of the district's population was of Polish ancestry).
But I agree, the swing to Bush is fascinating.
I would have thought most Polish-Americans would have been in favour of Reagan's foreign policy, even if they were Democratic on economic issues. But who knows.
Polish Americans liked the Polish commies about as much as Cuban Americans like Castro. Most viewed the PRP as an instrument of Russian occupation. More likely they were unionized industrial labor for whom Mondale was actually a good candidate, and were more reluctant to vote for Dukakis, who had weaker credentials in that area.