“The way the system works now is the same way that national packaged goods marketers work. Iowa and New Hampshire and South Carolina, e.g., are test markets. Small, inexpensive markets to start with — which allow a candidate to prove he can compete and, thus, gain funding.”
A primary debate process, with more debates, held on some similar pattern to the present primary schedule would serve the same purpose via the polling that would be done after and between the debates.
And the advantage is, with the actual vote held on the same day following the last debate, those who thought they made uo their mind after an earlier debate but have since changed their mind (which happens with the primaries now), would be able to put their final choice in their vote.
All nice and neat.
Except somebody will spend $100 million in advertising -- and they'll be the winner.
You won't be able to keep them from doing it either -- the First Amendment insures them that right.
The point is this: a single national primary day will result in the election of the candidate with the deepest pockets. And it will shut out any candidate without immediate access to big bucks.
I assume that isn't what you want.