07/17/2012 07:22 pm ET Updated Jul 18, 2012

New Hampshire Poll: Barack Obama's Lead Shrinks

President Barack Obama holds a narrower lead over Republican challenger Mitt Romney in New Hampshire, according to a new poll.

The WMUR Granite State poll, conducted by the University of New Hampshire Survey Center, finds Obama ahead of Romney by 49 to 45 percent. The president’s lead, which is within the survey’s margin of error, marks a decline since April, when the university pollsters found him ahead of Romney by nine percentage points.

The erosion of Obama’s lead may be attributable to his weakening job approval rating in the Granite State. While a narrow majority of New Hampshire adults approved of the president’s job performance in April (50 to 47 percent), they are now more closely divided, with 47 percent approving and 48 percent disapproving.

According to WMUR, the president "is still more popular than Romney." While 47 percent of New Hampshire adults said they have a favorable opinion of Obama, only 38 percent said they have a favorable opinion of Romney.

The poll also found that nearly one-fifth of New Hampshire’s sizable percentage of independent voters remain up for grabs -- a group that could well swing the state's electoral votes.

Live telephone interviews were conducted with 521 New Hampshire adults, with a subsample of 470 likely general election voters. The margin of error was 4.3 percent among adults and 4.5 percent among likely voters.

HuffPost Pollster’s trend estimate of the race, which takes into account all available public polling, shows Obama leading Romney by 48.4 to 45 percent.