Most of the states, 48 of them (except for Nebraska and Maine), are winner-take-all contests, where one candidate or another gets all of what are called electoral votes, which Parade magazine attempts to explain, as does the Wikipedia.
Basically, the number of members of the House of Representatives (based on population) plus the number of US Senators (2 per state) equals the number of electoral votes a state gets. The District of Columbia, where the nation’s capital, Washington, is (as opposed to the western state of Washington), also gets three electoral votes.
The candidate with more than 270 electoral votes (538 total electoral votes divided by two, plus one) becomes President. Getting on the ballot on each state is fairly routine for the Democratic Party (candidate is Hillary Clinton) and the Republican Party (Donald Trump). Only one other candidate is on the ballot in all 50 states, the Libertarian Party candidate, Gary Johnson. Jill Stein of the Green Party is running in over 40 states. Here’s a list of other minor party candidates.
The winner in November will be either the Democrat or the Republican. Not since 1860, when Abraham Lincoln won, running on the nascent Republican party, won the election. The Progressive Party ran former President Teddy Roosevelt against the Republican incumbent (and former TR Vice-President) William Howard Taft. Teddy came in second, and received 88 of 531 electoral votes. But Democrat Woodrow Wilson was elected.
1968 was the most recent time at third party candidate won electoral votes, George Wallace of the American Independent Party, who garnered 46 of 538 electoral votes. “The last third party candidate to win more than 5.0% of the vote was Ross Perot, who ran as an independent and as the standard-bearer of the Reform Party in 1992 and 1996, respectively.” Read more about third parties here.
[Blue is Democratic; red is Republican.]
Each state has its own rules about voting. The deadlines for registering to vote vary. Some allow early voting, before November 8, while others do not. The hours the polls are open are not the same. This is is the nature of federalism, which allows the states to maintain control of certain aspects of the process.
I will be voting in the election for our 45th President. I ALWAYS vote.
That’s enough for now – I worked on this piece before and it died when my computer whacked out – but if you have questions about the process, this old poli sci major will try to answer your questions.