In some states you have to decide which primary you are going to vote in and you register with that party a few weeks or months before the vote. You can switch parties every election if you like. If your nominee is safe you may choose to vote in the other parties election so as to attempt make sure they get the worse candidate possible.
In others you go to the primary poll and ask for a ballot for the party of your choice.
Having to buy membership before you can vote would be illegal here.
Voting in more then one primary would also be illegal. You could go to jail. Unless you are a democrat. Then vote six or more times and they will throw you a party and give you grants. (Yes, I am a tiny bit bitter about that.)
In others you go to the primary poll and ask for a ballot for the party of your choice.
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That’s the way it is in Texas. No citizen has to commit to a specific political party to register to vote.
Problem in Texas is the open voting, where folks of one party can vote for worst candidate of the other party; knowing that person would not be able to win against their favorite.
I’m often amazed when talking heads on TV say they are “registered” Independents (O’Reilly), Conservative (Hannity), GOP or Dem. ...Why does anyone have to express their political leanings before they can vote???
Good question, Jonty30.