AFAIK, primaries are not actual elections for public office; they’re elections happening inside of one of the two big parties, but since they’re so big, they’ve grafted their internal elections onto the government’s voting infrastructure. So, on a primary day, you may seem to be presented with candidates A_Dem, B_Dem, C_Rep and D_Rep, but in reality, if you’re are a Republican, you’re voting between C_Rep and D_Rep, and if you’re a Democrat, you’re voting between A_Dem and B_Dem. If you’re neither, you don’t really have a stake in that stuff, but you’re probably there to vote for various state or local elections or voter initiatives and the like.
In California, we briefly had a (stupid, IMO) law that anyone could vote for any party’s candidate in the primaries, and that brought on all sorts of weird gaming – Repubs were advised by their party to vote for the weaker Democrat so the Democratic candidate they eventually faced might be the weaker one, and vice versa. Very cynical stuff.
On the “real” election day, anyone can vote for anyone. (At least in California; I’ve never voted in any other state).
Well, there are checks and balances on that, including a preferential votiong system which means that if they make too outrageous a choice in those smoke-filled rooms, the voters can go for an independent or third-party candidate. Oddly, this most likely to happen in very “safe” seats.
In the cuirrent Australian election, it may happen in the seat of Wentworth, in Sydney’s Eastern Suburbs, which has been held by the Liberal Party or one of its predecessors since Federation in 1901. ABC News description of Wentworth
It is quite likely that the independent King will beat the Liberal Turnbull with Labor preferences. It is even possible that Labor could win the seat for the first time ever.
In Canada, elections are completely non-partisan; you don’t have to declare anything other than your name and address and prove your citizenship in order to vote. Also, national elections are entirely run by Elections Canada rather than the provincial and territorial electoral committees.
Parties are essentially private organizations, although anyone can join one of the parties by paying a nominal fee (in the case of the NDP, $10 for workers or $5 for reduced incomes).
Parties set their own rules for nominating candidates, and nominations are entirely run by the party with no government involvement. The riding association (membership of a party in one electoral district) typically votes for the candidate, although in unusual circumstances (a star candidate or a riding with next to no members) the party’s executive committee might choose a candidate. (If done lightly, this can piss a lot of people off.) In a contentious contested nomination, supporters of either candidate often go on recruiting drives, trying to sign up as many people as possible to vote for their candidate.
Any Canadian voter can run as a candidate; if they are not nominated, they can run as an independent. A $1000 deposit is necessary, which is usually paid by the party.
The system for choosing the leader varies from party to party. The delegate system means that the riding associations elect delegates to go to the national convention, where they vote for the leader there. (Usually the election of delegates is accompanied by assurances about which way they’ll vote.) In the one-member-one-vote system, all members of the party have the right to vote for the leader. In the NDP’s case, owing to the historical importance of unions and other ‘affiliates’ whose members are automatically members of the NDP, we compromised on a system that’s 75% weighted to one-member-one-vote, and 25% weighted to delegates from affiliates.
You don’t have to declare party affiliation in Tennessee but I am unsure about Oregon… I didn’t look at the form very closely and just marked myself as a Democrat.
Like others have said, you can register with a party in CA, but you don’t actually have to. The thing is, if you don’t register as a Republican or Democrat, there’s not a lot to vote for in the primaries, which I discovered after I changed party affiliated from Democrat to Green in 2001.
Here in Illinois, we don’t register with parties, but you have to pick either a Democratic or Republican ballot when you vote in the primaries.