Voting group

Regional Presidential Primaries and Mobile Voting
There are many similarities between politics and college/professional sports. I like sports and I especially like the NFL Playoffs and NCAA College Basketball Championship. When I compare the methods parties use to select their Presidential nominees with how professional/college sports crowned their champions, there is no contest (excuse the pun). Professional/College sports leagues do it better. Many popular reality TV shows (American Idol, The Bachelor, Survivor, etc.) also use multiple elimination rounds to decide on a winner.

Something to remember ... Political parties are private gain-seeking organizations and (IMO) governments should neither fund, nor run, partisan primaries. As we saw with Kamala Harris' nomination last year, the parties can run their nominating process anyway they want.

It is in a political party's self interest to create a fair, standardized, transparent, secure, and exciting (buzz, earned media, FOMO) process to select their Presidential nominee.

Voters, especially younger voters, will like this new way of selecting the party's Presidential nominee.

My vision for Presidential primaries ...
Political Parties should choose Party-run Regional Primaries. The Regional Primaries would be run between January and May, with four weeks between each regional primary. The order of the primaries would be selected by lot. The buzz and hype would be similar to the NFL Draft.
The primaries would be open to All registered voters. Parties currently have access to registered voter data.
The preferred method of voting would be through a secure mobile voting app. The technology is already here. The technology will be more mature and accepted by 2028. If a voter doesn't want to use the mobile app, mail-in and in person voting will also be available. In person voting would be limited. Perhaps one in person voting location in each Congressional District. In person voting would be run by the party, not the government.
Scoring
Each state will allocate delegates by their electoral college votes (x 10). No winner takes all states. After the state votes are tabulated, candidates will receive a proportion of the delegates based on their votes. I'm also a big fan of RCV, so Proportual RCV could also be used.
Vision
Likely outcomes of the new system. Many candidates will likely throw their hats into the ring. At the beginning of the process, no one can predict, with any degree of certainty, who will win. Even long shot candidates have a chance. Kinda like the 64th seed in the NCAA Basketball Championship.
Four, unrepresentative states (Iowa, New Hampshire, Nevada, South Carolina) will no longer have outsized importance. Every voter in every state can say that their vote mattered.
Because there will be no "winner takes all" states and the votes will be allocated proportionally, several candidates will most likely remain viable into the last regional primary. Using the March Madness analogy, the primary field could start with 32 candidates and dwindle to 16, then 8, and finally to 4 in the last region.
Money and name recognition will be important, but it will not be as important as it is under the current primary system. Any candidate can win. Money and special interest groups can no longer put all of their chips on one candidate. Local media and local new media will play a bigger role than under the new system.
If, for example, the Democratic Party decides to implement this system, and the Republican Party decides to use the current system, the Democratic Primary contest will be all over the news and internet for months. It will be exciting, with multiple storylines, interesting policy ideas, etc.
In the end, I believe the ultimate nominee will be fully "battle tested," and more competitive in the general election.
Hopefully, this new system will produce better nominees and restore the public's trust in the way we select our President.
Importantly, none of these suggestions require a Constitutional amendment, an Act of Congress, a state law, or a tremendous amount of money. It will also save state and local election administrators tens of millions of dollars.