Sen. Barack Obama, fresh from his win in the Iowa caucuses, has opened up a 13 percentage point lead over Sen. Hillary Rodham Clinton in the battle for votes in tomorrow's New Hampshire primary, according to a USA Today/Gallup Poll conducted in the state from Friday through yesterday afternoon.

Obama's surge, to 41 percent, is up from 32 percent in the last USA Today/Gallup New Hampshire poll, taken in mid-December.

Clinton had 28 percent and John Edwards 19 percent.

Howard Wolfson, a spokesman for the Clinton campaign, was asked about the USA Today poll and another New Hampshire poll also out yesterday showing Obama with a 10-point lead.

That tracking poll, by CNN and Manchester TV station WMUR, had Obama leading Clinton 39 percent to 29 percent over the past two days.

"I am confident and optimistic that we will do well," Wolfson said. "I'm not going to predict an outcome."

The race appears much tighter on the Republican side, with Sen. John McCain 4 percentage points ahead of Mitt Romney. The poll has a margin of error of plus or minus 4 percentage points.

McCain, who won the 2000 presidential primary in New Hampshire, had the support of 34 percent of those surveyed compared with 30 percent for Romney, the former governor of Massachusetts.

Mike Huckabee, who won the Iowa caucuses last week with the help of evangelical Christian voters, had 13 percent.

The surveys of 776 New Hampshire residents who are likely to vote in the Republican primary and 778 New Hampshire residents who are likely to vote in the Democratic primary were all completed after the results from Thursday's Iowa caucuses had been reported.