Here’s a closer look at the New Hampshire contest and its mechanics:
The primary is state-run, while the Iowa caucuses are party-operated meetings that begin at night and require a longer time commitment to vote. New Hampshire voters simply must go to polling stations, most of which will open in the early morning and close at 7 p.m. local time. Other polling locations will close at 7:30 p.m. or 8 p.m.
The northern New Hampshire hamlets of Dixville Notch and Hart’s Location will continue a tradition of voting and reporting their results minutes after midnight today, before everyone else. The Associated Press will report results as soon as they get them, though it won’t project a winner until after all polling stations have closed at 8 p.m.
The vote is open to registered Republicans and voters who haven’t declared a party preference. Also, residents who haven’t registered to vote may do so on primary day.
According to the office of New Hampshire Secretary of State William Gardner, there were 231,611 Republicans and 312,621 undeclared voters as of Dec. 14.
Gardner has predicted a turnout of 250,000 for the Republican primary, a little higher than the almost 240,000 ballots cast in the past two competitive Republican primaries.
Turnout was 239,793 in 2008, when Arizona Senator John McCain beat rivals including Romney. In 2000, there were 238,206 votes cast in the primary in which McCain defeated then-Texas Governor George W. Bush, who went on to become his party’s nominee and win the presidency.
Unlike in 2000 and 2008, this year’s Republican primary isn’t competing with a contested Democratic race for the attention of the 41 percent of voters who don’t declare a party preference. President Barack Obama, then an Illinois senator, lost the 2008 Democratic primary to then-Senator Hillary Clinton of New York by 2 percentage points. In the 2000 Democratic race, then-Vice President Al Gore defeated former Senator Bill Bradley of New Jersey by four percentage points.
Romney campaigned frequently in New Hampshire, where he also owns a home. He was governor of neighboring Massachusetts from 2003 to 2007 and placed second in the New Hampshire primary in 2008.
Former Senator Rick Santorum of Pennsylvania, a social- issues conservative who finished second to Romney in the Iowa Caucuses by eight votes, isn’t doing as well in New Hampshire because the state doesn’t have as large a bloc of evangelical voters. In the 2008 Republican primary, 23 percent of voters told pollsters they were born-again or evangelical Christians, compared with 57 percent in last week’s Iowa caucuses.