Still, Obama is staked to leads over the best-known Republican contenders. He leads Romney, 49 percent to 45 percent, and holds a six-point lead over former Arkansas Gov. Mike Huckabee, 50 percent to 44 percent. Obama has larger leads over former Alaska Gov. Sarah Palin (55 percent to 38 percent), former House Speaker Newt Gingrich (54 percent to 39 percent), former Minnesota Gov. Tim Pawlenty (53 percent to 38 percent), real estate magnate Donald Trump (52 percent to 40 percent) and Rep. Michele Bachmann (R-Minn). (51 percent to 39 percent). The poll also confirms that Romney has a slight advantage at the start of the 2012 Republican campaign: When Republicans and Republican-leaning independents were asked, open-ended, for whom they would vote in a GOP primary or caucus, 16 percent chose Romney, who was the only candidate to earn double-digit support. But only 43 percent of Republicans or Republican-leaning independents are very or somewhat satisfied with the choice of candidates for the GOP nomination. In April 2007, 65 percent of Republicans were satisfied with the candidates. The poll was conducted April 14-17 by Langer Research, which surveyed 1,001 adults, for a margin of error of +/- 3.1 percent. There were 432 Republicans and Republican-leaning independents, for a margin of error of +/- 4.7 percent.