New Hampshire primary results used to forecast presidents.
Then Bill Clinton came along. He lost to former Sen. Paul Tsongas in 1992, but won the White House.
Clinton showed the primary still can shape history, however. He overcame allegations of marital infidelity to rebound to second place in New Hampshire, embraced the "Comeback Kid" label and went on to become president.
"He lost, but he won," said Corey Lewandowski, state leader of Americans for Prosperity. "That's what brought him back into the race. That's still a win."
Political watchers don't see big surprises coming tomorrow, and expect Mitt Romney and President Barack Obama to claim victory.
Yes, Obama is on the ballot — though his lack of a serious Democrat challenger and a crowded Republican field may have caused some to overlook it.
"The surprise, if there's going to be one, might be on the margin of victory for Romney," said Dayton Duncan, author of "Grass Roots: One Year in the Life of the Presidential Primary."
The margin of victory often matters.
In 1968, Sen. Eugene McCarthy's anti-war candidacy pulled 42 percent in the Democrat primary against President Lyndon Johnson. Johnson won, but soon quit the race.
Four years later, in 1972, Sen. Ed Muskie won the primary on the Democrat side — but not by the margin analysts expected. Muskie ultimately would lose the nomination to Sen. George McGovern.
In 1992, political columnist Patrick Buchanan undermined President George H.W. Bush's re-election bid with a strong second-place showing in New Hampshire.
For decades, either the Republican or Democrat primary winner ended up president.
Since Clinton, New Hampshire's status as a crystal ball on November outcomes has faded. But that's not so true of its lasting influence on the presidential campaign.
In 2008, the primary resurrected the campaign of John McCain and made him "Comeback Kid 2." McCain would lose to Obama, but he earned the Republican nomination.