You obviously don't know much about Hillary's
liberal (sic) history - here and abroad - coups in Honduras, Libya, Clinton foundation involvement in Haiti, and on and on.

Prior to qualifying Sanders for our own caucus ballot, the Hawaii Democratic Party asked the Vermont Democratic Party for clarification of the senator's status as a member of good standing in his state party, since our own state law requires all candidates running for public office on a particular party slate to be a card-carrying member of that party. If he was not a member, then we were not going to list him for members' consideration in our March 26 presidential preference poll.

Vermont Democrats assured us that Sanders was now indeed a formal member of the party, and that if he failed to gain the 2016 Democratic presidential nomination, he would be amending his re-election paperwork for the 2018 Senate race to reflect that change of party status.

I'll have take them at their word at this point. (And really, what choice do we have?) Bernie Sanders is a Democrat.

The multi-party allure ... on the surface, it does make some sense.  Certainly, we consumers of all things are used to near overwhelming numbers when we go shopping or seeking anything.  Why not the same shopping approach when selecting our government officials?  I'm guessing that it has a lot to do with longstanding cultural tradition in this country as well as with a certain satisfaction level to date.  Occasionally, people like Perot and Nader and the Dixiecrats and even other international organizations such as the Greens try out the third-party route ... and don't forget the periodic flirtation as to third-party from Michael Bloomberg.  After some jostling here & there, the efforts fade or go away altogether.

Your statement, is a bit misleading, however.  There is no "basic right to vote" in the traditional sense (meaning, cutoff dates are unfair) in a political party's nominating process.  The Supreme Court said so in 1973 in Rosario v. Rockefeller (my emphasis in bold)

Petitioners challenge the constitutionality of New York Election Law § 186, which requires a voter to enroll in the party of his choice at least 30 days before the general election in order to vote in the next party primary. Though eligible to enroll before the previous general election, petitioners failed to do so, and were therefore ineligible to vote in the 1972 primary. The Court of Appeals, reversing the District Court, upheld the New York scheme, which it found to be a permissible deterrent against the practice of primary election "raiding" by opposing party members.

Held: New York's delayed-enrollment scheme did not violate petitioners' constitutional rights. Pp. 410 U. S. 756-762.

(a) Section 186 did not absolutely prohibit petitioners from voting in the 1972 primary, but merely imposed a time deadline on their enrollment, which they chose to disregard. Pp. 410 U. S. 756-758.

(b) The statute does not deprive voters of their right under the First and Fourteenth Amendments to associate with the party of their choice or subsequently to change to another party, provided that the statutory time limit for doing so is observed. Pp. 410 U. S. 758-759.

(c) The cut-off date for enrollment, which occurs about eight months before a presidential, and 11 months before a nonpresidential, primary, is not arbitrary when viewed in light of the legitimate state purpose of avoiding disruptive party raiding. Pp. 410 U. S. 760-761.

458 F.2d 649, affirmed.

STEWART, J., delivered the opinion of the Court, in which BURGER, C.J., and WHITE, BLACKMUN, and REHNQUIST, JJ., joined. POWELL, J., filed a dissenting opinion, in which DOUGLAS, BRENNAN, and MARSHALL, JJ., joined, post, p. 410 U. S. 763.