This will be a boon for urbanites, who are mostly liberal Democrats.
There could be some conservative candidates who choose to spend no money in the more expensive big markets and funnel all of their advertising to less expensive rural areas, but then that will just exacerbate the Red State / Blue State rift.
And how the heck do you handle a recount if the vote is close?
THAT is ANOTHER Constitutional quesion ...
Can a state [say MA] that participates in the NPV Compact DEMAND a recount in ALL 50 states and the territories if the initial result of the NPV goes the GOP way in a close election ???