More important, Romney was the first choice of tea party supporters (winning 41 percent of their votes) and self-described evangelical or born-again Christians (31 percent). And he carried every ideological band on the GOP spectrum, including 29 percent of those who called themselves "very conservative."
Former Pennsylvania Sen. Rick Santorum won all three of those categories in the Iowa GOP caucuses last week, where he finished eight votes behind the winner, Romney, who never rose above the midteens in polls of evangelicals, tea party backers, and the very conservative in entrance polls at that state's caucuses.
Of course, as a percentage, these self-described most-conservative voters were a smaller share of the electorate in New Hampshire than they had been in Iowa. But Romney's strategists were ecstatic, believing that the Granite State results show his potential to do well in South Carolina, a much more conservative state that holds its primary Jan. 21.
Anger at Obama
"The big question heading into South Carolina and Florida is whether Romney will perform as well among these key Republican groups as he did in New Hampshire," wrote Washington Post pollster Jon Cohen in his breakdown of the exit-poll numbers.
If those numbers were encouraging on some levels for Romney, they also showed that Republicans and independents in New Hampshire are angry with President Obama and ready to turn him out. (Still, even GOP strategists think New Hampshire, where Obama won easily over John McCain in 2008, will be competitive in November.)
The data in the poll, which was jointly sponsored by the Associated Press and the major TV networks, came from interviews with 2,766 voters as they left polling places across the state. The margin of error was plus or minus 3 percent.
It is possible that the New Hampshire results were skewed by Romney's homeboy status. After all, he has a summer home in New Hampshire and was governor of neighboring Massachusetts, where many who voted Tuesday commute to work.
Already, the campaign has moved south, and three rivals from the right (Santorum, former House Speaker Newt Gingrich, and Texas Gov. Rick Perry) are pounding on Romney, hoping to stop a candidate that many conservatives see as too moderate and tied to the GOP establishment to offer a compelling contrast to Obama.
Strong conservatives and evangelical voters were 34 and 60 percent, respectively, of the South Carolina GOP primary electorate in 2008, that year's exit polls say, compared with 24 and 21 percent, of Tuesday's electorate.
There also were encouraging signs Tuesday for Romney in a potential general-election matchup. Independents, who can vote in either party's primary in New Hampshire, were about 47 percent of the electorate in the GOP primary; Paul carried 32 percent of them, to 29 percent for Romney.
The bad news for Romney is that six out of 10 voters went with somebody else, and 55 percent of them said they would be disappointed if the former Massachusetts governor winds up the nominee. That's actually normal during a competitive nomination contest that hasn't been decided yet, said Monmouth University pollster Patrick Murray, who analyzed the exit-poll data for NBC News on primary night.
But, Murray wrote, "the real issue is whether less resolute Republicans - i.e. libertarian-minded voters - will do the same. According to the exit poll, the problem may not be winning over supporters of Gingrich, Santorum and company - these voters are about evenly divided on whether they would be happy with a Romney nomination. The bigger challenge would be convincing Paul voters, 68 percent of whom who would be dissatisfied if Romney was the Republican standard bearer. The threat of a libertarian third party candidate poses real trouble."
In other words, Paul, the Texas congressman who is considered unlikely to win the GOP nod, could become a wild card. He has said he has no plans to run as a third-party candidate in November - but he won't rule it out either.
Contact politics writer Thomas Fitzgerald at 215-854-2718 or email@example.com or @tomfitzgerald on Twitter. Read his blog, "The Big Tent," at www.philly.com/BigTent.