I mean Republicans won Georgia Senate runoffs in 1992 and 2008 after Democrats won the White House. It seems like runoffs usually go against the party that did well nationally in the November election because the losing party is more motivated to turn out. But as we all know, Trump threw a wrench in that...
The difference here can be attributed to changing party coalitions more so than Trump's presence. The fact is that the GOP was nowhere near as reliant on supercharging rural turnout/receiving sky-high margins out of rural/small-town GA in those elections given their strength in areas containing the highest concentration of the type of voter most likely to turn out in a runoff election:
(Paul Coverdell's victory map in the 1992 runoff election)
2008 was even more lopsided — while Democrats had bled considerable support in ancestrally Democratic (esp. in the Coastal Plains) or only modestly Republican-leaning areas (in the North), the GOP had retained or broadened its support in ruby-red Atlanta suburbia/exurbia. These elections were held during a time when college-educated white voters were not notably less Republican than non-college-educated voters and do not serve as particularly pertinent points of comparison.
Poll
