The New Hampshire primary is the first in a series of nationwide political party primary elections held in the United States every four years (although the Iowa caucus is held earlier), as part of the process of choosing the Democratic and Republican nominees for the presidential elections to be held the subsequent November.
Although only a few delegates are chosen in the New Hampshire primary, its real importance comes from the massive media coverage it receives (along with Iowa, which holds the first caucuses); in recent years the two states received about as much media attention as all other state primaries combined. An example of this massive media coverage has been seen on the campus of Saint Anselm College, as the campus has held multiple national debates and have attracted media outlets like Fox News, CNN, NBC, and ABC. The publicity and momentum can be enormous from a decisive win by a frontrunner, or better-than-expected result in the New Hampshire primary. The upset or weak showing by a front-runner changes the calculus of national politics in a matter of hours, as happened in 1952 (D), 1968 (D), 1980 (R), and 2008 (D).
Since 1952, the primary has been a major testing ground for candidates for both the Republican and Democratic nominations. Candidates who do poorly frequently drop out, while lesser-known, underfunded candidates who do well in New Hampshire suddenly become serious contenders, garnering large amounts of media attention and campaign funding.
It is not a closed primary, in which votes can be cast in a party primary only by people registered with that party. Undeclared voters — those not registered with any party — can vote in either party primary. However, it does not meet a common definition of an open primary, because people registered as Republican or Democrat on voting day cannot cast ballots in the primary of the other party.