Once every four years, the small agricultural state of Iowa becomes the epicentre of American politics.
For one weekend, the normally quiet downtown of state capital Des Moines is swamped with candidates, political staff, academics and journalists. Hotel room rates quadruple to as high as US$600 (S$855) a night.
That Iowa draws this much attention simply comes down to the fact that it is the very first state in the nation to hold an election in the drawn-out process of picking a party nominee for the presidential polls.
When Iowans head to caucuses on Monday night (this morning, Singapore time), they will cast the first ballots in the campaign. Their votes are thus the first true test of a candidacy.
A small state with a politically engaged populace, it is an important indicator of a candidate's national viability and how well he or she can run a campaign. If a candidate can't do well in Iowa, then how can he or she expect to win the White House?
Win against the odds and it could make a campaign. When Senator Barack Obama won here in 2008, it suddenly made him competitive against the early front runner, Mrs Hillary Clinton. Four years earlier, Mr John Kerry rode the momentum from winning Iowa to the Democratic party nomination.
This time around, the choices are even starker. The ballots for both Republican and Democratic parties offer voters a choice between an insider and an outsider.
Businessman Donald Trump on the Republican side and Senator Bernie Sanders on the Democratic side have both defied conventional wisdom to emerge as strong contenders. A victory for either one will send shockwaves through their parties.
If Mr Trump wins, it will dispel nearly all doubts about the seriousness of his candidacy. If Mr Sanders wins, the inevitability of Mrs Clinton's nomination will come into question.