DOVER, N.H. » After weeks of suggesting Barack Obama was born in Africa, Donald Trump hastened to boast that he had forced the Democratic president to release a detailed Hawaii birth certificate disproving that claim, painting an apparent setback as a victory within minutes of arriving in the first-in-the-nation primary state.

The developer and reality TV show host, who says he is considering a White House run, again showed the difficulty establishment Republicans are having in controlling the early stages of their wide-open nominating contest. He also proved himself a nimble messenger, or spinner.

"Today I am very proud of myself because I have accomplished something that nobody else has been able to accomplish," Trump told reporters Wednesday shortly after his black and red helicopter, emblazoned "TRUMP" on the side, touched down in Portsmouth.

He arrived not long after the White House released the president's long-form birth certificate from Hawaii. He said he was honored "to have played such a big role in hopefully — hopefully — getting rid of this issue. Now, we have to look at it, we have to see, is it real."

Trumps said he hoped the birth certificate "checks out beautifully," but he used the opportunity before television cameras to again sharply criticized Obama on several fronts, including Libya policy and gasoline prices. He also raised questions anew about Obama's educational record and how he got into college. But he again offered no proof of anything amiss.

Trump's blistering attacks on Obama — including raising widely debunked rumors that the president was born abroad — have piqued the interest of some Republican voters. He has seen his standing in some polls grow in the months since he first dangled a presidential candidacy before a GOP primary electorate looking for a leader to aggressively challenge the Democratic president.

Many rank-and-file Republicans still dismiss Trump as a non-serious distraction.

But as he easily grabs headlines, other potential candidates are playing a more cautious game, and most don't seem eager to talk about him. They've been distancing themselves from the so-called "birther" claims in recent days, and most weren't eager to weigh in Wednesday.

Sarah Palin, the former Alaska governor, sent a brief tweet that said: "Media: admit it, Trump forced the issue. Now, don't let the WH distract you w/the birth crt from what Bernanke says today. Stay focused, eh?" That was a reference to Federal Reserve Chairman Ben Bernanke's news conference.

And former Massachusetts Gov. Mitt Romney said on Twitter: "What President Obama should really be releasing is a jobs plan."

Less than a year before Iowa and New Hampshire Republicans become the first to vote in the race, the GOP field is far from set. There's no true front-runner and no single establishment candidate. That leaves ample room for attention-getting events by less orthodox politicians such as Trump and third-term Rep. Michele Bachmann of Minnesota.

Romney, who lost the nomination in 2008, former Minnesota Gov. Tim Pawlenty and former House Speaker Newt Gingrich all have taken initial steps toward full-fledged runs but none has emerged as the candidate to beat. Many Republicans expect Bachmann and former Sen. Rick Santorum to make their interest official. They also are waiting to hear from former Utah Gov. Jon Huntsman and Indiana Gov. Mitch Daniels. The 2008 vice presidential nominee, Palin, and the Iowa caucus winner, Mike Huckabee, have dropped hints they will not run, but Republican insiders say no one is sure.

Mississippi Gov. Haley Barbour became the latest Republican to opt against a presidential run this week. 

"This is shaping up to be a wacky year," said Scott Reed, who managed Republican nominee Bob Dole's 1996 campaign and had been advising Barbour. It's the most wide-open GOP primary in four decades, he said, and the eventual nominee conceivably could jump in as late as September.

"There is still room for someone to emerge as the conservative alternative to Romney," Reed said.

Most veteran Republicans don't believe that person will be Trump, the thrice-married, much-caricatured developer who has donated heavily to Democrats in past years and switched his stands on key issues such as abortion.

Karl Rove, the top political adviser to President George W. Bush, calls Trump a "joke candidate."

Jennifer Horn, a 2008 Republican congressional nominee from New Hampshire, said in an op-ed column that Trump has flip-flopped on major issues and is not a credible candidate. If Republicans allow him to "hijack the primary process then they deserve exactly what they get," she wrote.

Over the years, Trump has given thousands of dollars to Democratic candidates, including New York Sens. Chuck Schumer and Kirsten Gillibrand and Senate Majority Leader Harry Reid of Nevada.

Trump talked of running for president as a third-party candidate in 2000, and he made a brief splash with a 1988 New Hampshire speech that some took as a preliminary Republican candidacy.

In New Hampshire on Wednesday, Trump breezily dismissed his critics. 

"I think I'm quite conservative as a Republican," he told reporters in Portsmouth. In at least two instances, he said, "I'm leading the polls." Forcing Obama "to finally come out and issue a birth certificate can only help," he said.

Trump said he has given campaign money to "many Republicans, many Democrats. And I think there's something nice about that," because it promotes bipartisanship.

As for switching his stand on issues, he said, "My views change. ... I tell people, you have to remain flexible because the world changes."

He also turned the conversation to Obama.

"Nobody even knows what's going on in Libya," Trump said. He said Obama claims to have little control over gasoline prices, but "he does if he gets on the phone or gets off his basketball court or whatever he is doing at the time."

After holding court before reporters, Trump traveled to several other stops, all within a nine-mile radius of the Portsmouth airport.

He spent a few minutes shaking hands at a Portsmouth diner but spent little time in conversation. Passing by a table of older men, he waved and said, "Why aren't you at work?" 

"We're retired!" answered the group of former workers at the Portsmouth Naval Shipyard.

"Don't touch Medicare, right?" Trump said, moving on without waiting for an answer.

Joe Lovell, of Somersworth, said seeing Trump arrive by limo was a surprise in this state that values close contact with presidential hopefuls.

Asked what he thought of Trump, he said, "Nice hair."