[thomaslord]

Depends how you define "a lot" - rural areas make up 20% of the population of the US, so you might need some rural voters but not necessarily a lot (percentage of actual voters may vary, but I don't have those numbers handy).

I'm not totally sure that your numbers are correct, at least for presidential elections. Philadelphia's split in 2020 was 81% for Biden and 18% for Trump.