D presidential margin in Madison WI versus Washington DC (see below for further details)

[Sol]

In 2020, Democrats got 84.1% in Madison and 92.2% in DC. That's a substantial hurdle to jump and IMO it's hard to see how.

The easiest thing to imagine is Republicans running a candidate who's strong with Black voters, but IMO Black voters in D.C. are probably more socially liberal and more closely tied to Democrats than Black voters in other cities -- plus that's hard to imagine regardless.