The "Delaware Plan" for primaries?

Yet another primary reorganization proposal from Michael Barone:

If (every state moving its primary forward) turns out to be the case, we will have moved toward a de facto early national primary, which not only devalues retail politics but forces voters to make a decision all at once without seeing how candidates stand up under the rigors of campaigning. Is there an alternative? My favorite is the Delaware Plan, which came close to being endorsed by the 2000 Republican National Convention. It has four rounds of primaries or caucuses, with the 13 smallest states voting in March, followed by the 13 next largest in April, the next 12 in May, and ending with the final 12 largest states voting in June. This would leave plenty of room for retail politics, with candidates able to pick the states where they might run best.

Voters in later states would be able to judge how candidates run the gauntlet. The nominations could not be clinched until June, since the 12 largest states have 60 percent of the nation's population. The parties could endorse this system at their national conventions. Or if there was bipartisan consensus, Congress could impose it as federal law. Iowa and New Hampshire have been disproportionately powerful for 30-plus years now. But maybe not forever.