@MichaelG
>> "If that is the case, then primary elections should be regulated in the same way as government elections."
You still do not seem to get it. Primary elections are not government elections, and should not be regulated as such. This is because primary elections are private elections by private entities. The Democratic Party is not a government institution, but a private organization and therefore have the right to choose whomever they please as their candidate, in whichever way they deem fit. The same for any other party.
This is a right endowed by the First Ammendment of the U.S. Constitution: the people have the right to peaceful assembly and freedom of speech. As I mentioned in another post this is no different than you getting together with a bunch of friends and deciding to pick your own candidate for President (after all, anybody who fits the requirements can run). The government cannot tell you who to choose for your candidate nor how to choose him; you may want to choose yourself as a candidate (as independent candidates do) and nobody can tell you otherwise as long as you comply with the requirements. A political party is no more than a (possibly large) group of people that organize to choose and support a candidate for an office -- its like a big club.
Sure, some large political parties may have become corrupt during the years, but regulating them is tricky since any law that affects private entities making private decisions will necessarily affect you and I and any individual citizen.
-dZ.