WI: non partisan primary for president

[Polkergeist]

Lets say that all 50 states adopt non-partisan primaries which let the top 2 candidates go through to the general election. How would presidential elections change ?

[Blerpiez]

Then parties would probably schedule earlier primaries and nominate someone to run in all the primaries.  If you have enough support in one state, you can run two candidates in the primary and leave the other party out of the election, but those are already safe states