Party registration
The answer to the questions about registration is that the process and rules are different in the various states. Yes, I know that to outlanders it is incredible that the rules are not uniform nationally, but you have to remember that the United States of America is, as the name implies, first and foremost a union of states each and all of which have certain sovereign rights and privileges, among which are those pertaining to elections. I suppose by now everyone knows that there is no uniform ballot used nationally, or even for that matter within states -- each local jurisdiction is in charge and does its own thing.
Anyway, the way it goes in Maryland is approximately the way it goes in most places, in general, although there may be differences in the details. When you take up residence in a new election district, or when you attain the minimum voting age (18), you must register to be allowed to vote. This is generally done with the burocracy which runs elections; here it's called the Board of Election Supervisors, and there is an office in each county seat. You have to go there, show proof of age and citizenship (via a birth certificate, and a naturalization certificate if you are foreign born) and fill out some forms and you receive a voter's card which shows you are registered and tells you where to go to vote. You also declare a party, or independent. There is a deadline to be met. This may be as long as several months before the next election, or as short as the same day as the election, depending on local law. Last year, in order to increase voter registration, Maryland adopted a new policy that allows citizens to register at the Dept. of Motor Vehicles when they go there to renew their drivers license, on the excellent theory that since practically everybody goes to the DMV every few years, they can kill two birds with one stone. This has greatly increased the level of registration, as lots of people just didn't go to the trouble of going to the Elections Board. When you go to the polls to vote, the elections judges have a copy of the voter roll for that precinct and they check you off on the list when you report to them (so you don't vote twice). If you want to change parties or correct something else, you do it then and there, as they are empowered to make the change.
There is no compulsion to vote. Elections are nearly always on Tuesdays and the law requires that employers must allow employees 2 hours off to vote. The hours are usually 8:00 a.m. to 8:00 p.m. Primary elections (those to choose the candidates of the various parties) are usually a month before the general election. I don't know what they do in other states, but in Maryland, the elections judges have a record of who voted in each election. If you fail to vote in a certain number of elections (I think 5 successive general elections) you are dropped from the election rolls (I believe on the presumption that you are dead) and would have to re-register if you wanted to vote.
