The Republican Party and Democratic Party have all the same rights as the Liberatarian Party the Green Party and the American Nazi Party...
They're "private" parties who allow their registered members to cast a vote for their favorite candidate but ultimately the leaders in the party determine who has the best chance of winning and puts them forward as a presidential candidate.
The confusion here seems to be people thinking that political parties are government operated and that primaries are legitimate pre-voting or something.
People are ignorant, they get their "facts" from Facebook memes and yeah, kids have no idea what capitalism actually is or experience in the real world. You can poll the same kids and ask them "should everyone automatically receive $10,000/week in America" and they'd also say 'yes'.