Always remember that policy universally is promoted to further the agenda of a given party! Many republican politicians opt for the abolition of early/absentee voting, and democrats the opposite. Bear in mind that these policies are not just ideological rhetoric, but political play, intended to benefit the ruling party rather than the wider people.
The map is nonsense. Democrats take advantage of early voting for so many reasons, Republicans prefer in-person election day voting for their own reasons.
There are many more Democrats than Republicans, they just don't vote as much. The map.could easily be labeled: what would happen if every barrier to voting was removed vs what would happen if Republicans were allowed to implement all of the voter suppression tactics they can imagine.