Maricopa has seen large increases in both R and D voter registrations since 2016: R up 3.7% (gain of about 29,000), D up 7.9% (gain of about 39,000). Indies are up there too, but by less (about 15,000).
So if we go by differences in registration totals, it’s probably around 47% D, 35% R, 18% I for those new early voters. As with all EV, of course nobody yet knows how the actual votes went.
Another correction (I need to check my math today): Maricopa had more like a 49,000 increase in Rat registrations between 2016 and 20188, not 39,000.
As Maricopa goes so goes (probably) the state of Arizona as a whole, so it is important to focus on.