(CNN)-Former Massachusetts Gov. Mitt Romney tops a new WMUR Granite State Poll, with more likely Republican primary voters saying they'd support him in the first-in-the-nation primary state. His first-place showing in the poll hasn't wavered since February 2009.
Minnesota Rep. Michele Bachmann took over second place in the survey but still trails Romney by double digits.
More than one-third of likely Republican primary voters–35 percent– said they would vote for Romney, who also sought the GOP nomination in 2008. Twelve percent said they'd back Bachmann.
But support for the three-term congresswoman has increased by 8 percentage points since a well-received performance at the first CNN/WMUR/New Hampshire Union-Leader GOP primary debate and the formal announcement of her presidential bid in June.
With single-digit support, Texas Rep. Ron Paul and former New York Mayor Rudy Giuliani, who has not announced a bid for the 2012 Republican nomination for president, are tied at seven percent in the poll. Former Minnesota Gov. Tim Pawlenty and former Alaska Gov. Sarah Palin, another candidate still mulling over a bid, are also all tied up at three percent support each.
Two percent of likely primary voters support both former Utah Gov. Jon Huntsman and businessman Herman Cain. One percent back former House Speaker Newt Gingrich. Former Pennsylvania Sen. Rick Santorum polled below one percent support.
The top pick for Republican primary voters fares well against incumbent President Barack Obama in the poll, and better than any other potential GOP nominee: Romney leads Obama 47 to 43 percent in a hypothetical matchup. But the four-point margin falls within the poll's sampling error, indicating the match is statistically tied.
Most voters simply haven't made up their minds. Three-quarters of voters likely to vote in the first primary in the nation say they're still trying to decide whom to support for president.
And of all those questioned, two in 10 know whom they wouldn't support: Sarah Palin. Twenty-three percent of likely Republican primary voters say they would not vote for the 2008 GOP vice presidential nominee under any circumstances-more than any other GOP candidate in the field.
The WMUR Granite State Poll was conducted by the University of New Hampshire Survey Center from June 21-July 1 by telephone among 773 New Hampshire adults. It has a sampling error of plus or minus 3.5 percentage points. The poll included 357 likely 2012 Republican primary voters with a sampling error of 5.2 percentage points.