My post above describes the primary procedure for two neighboring states with closed primaries-New York State and Connecticut. The purpose of all this was to see if Sierra Song's posted story could possibly occur. As has been proven, this story could NOT occur in New York State, which is the state Hillary is running for Senate. So the story has been proven to be utterly false, as Setanta and others accurately stated early in this thread.
However, since the subject of primaries in other states has been raised, I will now deal with the primaries in other states in a general way, and answer Joe's post as well.
Up until 1990 or so, most states had closed primaries similar to New York State and Connecticut. You had to be a member of a party by Primary Day to vote in that party's primary. Incidentally, back then registering to vote even in the general election in November was not so easy to do-deadlines to register were usually in mid or late September, before a lot of people became interested in the races. A lot of people were left out on Election Day because they had not gotten around to register.
As pressure grew to make voting on Election Day easier, a related movement occurred to make it easier to vote in party's primaries as well. So the concept of "open primaries" took hold. The idea was to eliminate the requirement of making the voter register with a political party before voting in a primary.
Here is an excerpt from
Wikipedia.
Quote:Open. Voters may vote in primaries of a party of their choice, the choice to be made at the voting booth. When voters do not pre-register for a party, this is called the pick-a-party primary because the voter can select which party he wishes to vote in on election day. In other open primary states, voters pre-register their party preference but the information is only used by parties for mailing lists and is non-binding.
Please go to the link because it has a chart which says which states have closed primaries like New York State, and which have these "open primaries". Joe's Illinois has a "loosely enforced" system where the person must vote in the primary of the party whose primary he voted in before, but as he has shown, in actual practice it really is a "pick-a-party primary" system there.
So the story Sierra posted could theoretically have occurred if Hillary was running in any of a number of states with these open primaries-but not New York State, where Hillary is running.
PS: Massachusetts has a closed primary-you must be registered as a member of the party in whose primary you are voting-but you can register or change your registration right at the polling place. However, Massachusetts is not New York State, where you cannot do that. And Hillary is running in New York State.