How do each state's primary election results become one candidate for the national general election?

When each state votes during a primary election, one or two candidates are elected for a subsequent general election. But how do all the candidates from all the states become "one" national candidate for the general election in Nov?

mule0331:
The parties watch how people vote, and the party then nominates it's own person, based on poll results.

kt_b_blue:
The national party decides who to throw their support behind on the basis of the primaries.

For example, the democrats have Obama and Hillary as frontrunners in their primaries. They cannot support two candidates for presidency against the republicans; so primaries are held to help parties determine who has the best shot. Often the 2nd choice candidate gets billed as the Vice President.

So if Obama wins primaries, then there is a good chance Democrats will pull him for the ticket in the national election in November. It would work the same way for Republicans with McCain and Giuliani.

RTO Trainer:
Primary votes become delegates at the party convention. Delegates, much like the electors in the Electoral College, go havikng agreed to represent one candidate or another. They are not however bound to that and may change their minds, but it's not common

It's the votes in the convention that actually select the candidate and that usually reflects the primary. It's been decades since there was a "brokered" convention where they actually had to make a deal, trading delegates (votes) for support form the other candidates.

Scott B:
The nomination for the presidential candidate is made at the party's national convention. There are delegates to the convention from each state. In theory they cast their votes in accordance with the way the voters in their state voted. The results of that voting determine the party's nominee for the general election.