In addition to Jay Johnson's fluke win in '96, it also sent one of the two last Catholic Priests to serve in Congress, the very liberal Rep. Fr. Robert Cornell, who served 2 terms from 1975-79 (he knocked off a freshman Republican in the Watergate landslide, but lost running for a 3rd term to Toby Roth). Prior to that, it had last elected a Democrat in 1942, LaVern Dilweg, who served a single term before losing to longtime Rep. John Byrnes. The problem with the 8th is that it is only competitive when the incumbent leaves, so it isn't out of the question a 'Rat could win it, but lasting longer than a single term isn't likely.
David Donald, in his 1999 biography of Lincoln, explained that in Lincoln's day, it was very common, almost the rule, for a man to serve a single term in the House. The People knew what they were doing and turned over their House seats about as often as they turned their mattresses, and for pretty much the same reason.
I had completely forgotten that someone had served in the WI-08 between Toby Roth and Mark Green.