(CNN) -- A poll released Monday indicates Mitt Romney and President Barack Obama are tied in the battleground state of New Hampshire.

Likely voters in the Granite State are split 47 percent to 47 percent, according to a Suffolk University/7News survey. Two percent of voters support Libertarian nominee Gary Johnson, while 4 percent are undecided.

The poll comes a few days after a survey by American Research Group on Friday showed Romney with 50 percent and Obama with 46 percent, a margin that fell within the poll's sampling error.

Both surveys were conducted entirely after the first presidential debate, which was held in Denver on October 3. The two candidates face off again for the second debate Tuesday in Hempstead, New York.

While Obama had largely maintained a steady advantage over Romney in New Hampshire for much of the campaign, the race has grown tighter in recent weeks. Romney gained a modest bounce in several swing states after his widely applauded performance at the first debate.

The new poll also indicates Obama fares better than Romney on personality and foreign policy, but the Republican nominee edges out the president, 45 percent to 42 percent, when voters are asked which candidate had the best plan to fix the economy.

CNN rates New Hampshire, with its four electoral votes, as a "toss-up" on its Electoral Map.

With the race so close, New Hampshire is one state where support for Johnson, the Libertarian candidate, could prove decisive in the final results. David Paleologos, director of the Suffolk University Political Research Center in Boston, said Obama will likely benefit more than Romney from Johnson voters.

"Politics is full of ironies. Gary Johnson voters are predisposed to voting against the incumbent president, but Johnson's presence on the New Hampshire presidential ballot is actually helping Obama," Paleologos said. "Those anti-incumbent voters - at least right now - aren't finding their way to Mitt Romney."

The poll comes the same day as a new survey suggests the race for the White House is a dead heat nationwide. A CNN Poll of Polls that averages seven nonpartisan, live operator, national surveys conducted entirely after the first debate indicates Obama at 47 percent and Romney at 48 percent among likely voters.

For the New Hampshire survey, Suffolk interviewed 500 likely New Hampshire voters by telephone between October 12 and 14. The poll's sampling error is plus or minus 4.4 percentage points.

 -- CNN Political Editor Paul Steinhauser contributed to this report.

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