The latest Granite State Poll released by WMUR shows the race between Barack Obama and Mitt Romney tightening to within the margin of error in New Hampshire, with the incumbent leading Romney by a mere four percent of the vote (49% to 45% with a 4.3% margin of error).

President Obama’s favorability and job approval ratings both slipped by several percentage points in this latest poll, with 53 percent of respondents saying they disapprove of the way that Obama has handled the economy. Additionally, a hefty 57 percent of voters surveyed believe the country is heading in the wrong direction.

“The polling is reflecting a momentous shift toward Gov. Romney in the Granite State,” said New Hampshire RNC Spokesman Tommy Schultz, “Our Victory program’s expanding grassroots organization and our campaign’s central focus on turning around the economy have clearly resonated with the voters in New Hampshire.”

Earlier in the week, Romney chief pollster Neil Newhouse of Public Opinion Strategies released a memo analyzing some other recent polling data, drawing several conclusions about Obama’s vulnerability.

“Four years ago today, candidate Barack Obama led John McCain 47.0%-42.5% (+4.5%) in the Real Clear Politics average of polls. Today, the race is even tighter for now President Obama. The most recent Real Clear Politics average puts the race at 46.8% Obama-44.4% Romney (+2.4%),” wrote Newhouse, “And, for the incumbent President to be polling well below the 50% mark does not bode well for his re-election prospects.”

Newhouse also sought to demonstrate that the President’s recent barrage of attacks on Mitt Romney’s record at private equity firm Bain Capitol have been largely ineffective, writing, “[I]f the point of the Obama negative onslaught is to undercut the Governor’s advantage on handling the economy, recent polling would indicate it has fallen short. In the most recently released Washington Post/ABC News Poll (conducted July 5-8), Governor Romney leads President Obama 48%-45% on which candidate would better handle the economy.”

These new numbers confirm that New Hampshire is likely to be a top battleground state in the race for the White House, with both candidates seeking to influence the few Independent voters likely to decide the race.