By Steve Holland
WASHINGTON (Reuters) - Leading Republicans are mounting an attack on real estate tycoon Donald Trump, worried that his flirtation with a 2012 presidential run hurts their chances to field a serious challenge to Barack Obama.
Many Republican officials doubt the billionaire and celebrity TV star known as The Donald actually wants the pain and suffering that comes with a presidential campaign. They see him as a self-promoting publicity hound and his talk of a White House bid as a stunt drawing more attention to himself.
But polls show Trump getting a bounce from his highly public consideration of a campaign and his foray into "birther" politics, the idea some conservatives cling to that Obama was born in Kenya instead of Hawaii and so can not legally hold the presidency.
Concerns voiced by party elites suggest they are worried that the news media's fascination with Trump is crowding out some of the attention normally bestowed on the most serious of the Republican candidates.
Even if Trump emerged victorious as the Republican nominee, influential party players seem to doubt that he'd be able to defeat Obama.
Karl Rove, who was the architect of Republican George W. Bush's two presidential victories, called Trump a "joke candidate" for focusing on Obama's birth certificate.
"The guy is smarter than this," Rove told Fox News.
The Club for Growth, a conservative economic group, pointed to a statement that Trump had made in the past in support of government-run healthcare to denounce him as a liberal.
"Donald Trump for President? You've got to be joking," said Club for Growth President Chris Chocola. "Donald Trump has advocated for massive tax increases that display a stunning lack of knowledge of how to create jobs."
And conservative newspaper columnist George Will told ABC News' "This Week" online "Green Room" segment that Trump is a "blatherskite.""
"That is a word my grandmother was fond of as someone who blathers promiscuously," Will said.
All this leads Jennifer Cook, a political expert at the non-partisan Cook Political Report, to conclude: "It does seem that the GOP establishment is now engaged in a serious effort to undermine Trump's candidacy."
Trump is waving all the criticism aside, and holding interview after interview to rip Obama, Middle Eastern oil barons, Bush and even China.
"If we stop buying from China, China will go down like no other country has ever gone down before," he told Reuters last week. "China needs us more than we need them."
And last but not least, there is Mitt Romney, the wealthy former Massachusetts governor who many see as the Republican front-runner for the 2012 race.
"Well, I'm a much bigger businessman," Trump said on CNN's "State of the Union". "And I have a much, much bigger net worth. I mean, my net worth is many, many, many times Mitt Romney. And I don't know Mitt Romney. I really don't know him. So I'm not saying good or bad."
Still, Republican pollster Whit Ayres said Trump is getting a look from Republicans in search of a fresh face for 2012.
"There's unhappiness with the prominent names that are currently in the field. And when somebody comes along who already has high name identification, who sounds like he would be that new voice, a certain proportion of people gravitate to it," Ayres said.
A poll last week by Public Policy Polling said Trump led the Republican field with 26 percent, followed by 17 percent for former Arkansas Governor Mike Huckabee, 15 percent for Romney, 11 percent for former House of Representatives Speaker Newt Gingrich and 8 percent for former Alaska Governor Sarah Palin.
Republican strategist Scott Reed said Trump's poll numbers are proof that the Republican Party nomination "is wide open" and that Republicans should welcome him to the debate because some of the issues he raises are important.
"He speaks with some real common sense, especially to independent and (conservative) Tea Party voters," Reed said.
(Editing by Kieran Murray)