Let the Dems do it. I love to see them moving in the opposite direction of the solution to their problem. If they wanted real reform, they'd have a national primary on a single day so that no state had disproportionate influence, and no state was politically neutered by the process.
A compromise would be to select the states at random and put them in order from 1 to 50. A primary schedule could be set with 5 primary days, (such as every other Tuesday for 10 weeks.) Approximately 20% of the population of the country would hold a primary each Tuesday starting at the top of the list.) The schedule would change each election year.
BTW, the caucuses and straw polls would still be important.....