By Peter Wallsten

Washington Bureau--After a summer of health care battles and sliding approval ratings for President Obama, the White House is facing a troubling new trend: The voters losing faith in the president are the ones he had worked hardest to attract.

New surveys show steep declines in Obama's approval ratings among whites--including Democrats and independents--who were crucial elements of the diverse coalition that helped elect the country's first black president.

Among white Democrats, Obama's job approval rating has dropped 11 points since his 100-days mark in April, according to surveys by the Pew Research Center for the People & the Press. It has dropped by nine points among white independents and whites over 50, and by 12 points among white women--all voter groups that will be targeted by both parties for support in next year's mid-term elections.

"While Obama has a lock on African-Americans, his support among white voters seems to be almost in a free-fall," said veteran Republican pollster Neil Newhouse.

Strategists in both parties blame Obama's decline on growing discontent with his policy agenda, particularly after a month of an often rowdy debate over his proposed health care overhaul, in which conservatives accused him of being a "socialist." It is likely that Obama's ratings would rise again if he succeeded in winning passage of health care legislation this fall.

But the drop in support among whites also comes as some conservatives have escalated their efforts to provoke and nurture controversies that have the potential to further erode Obama's standing among centrists.

Dominating conservative talk shows last week on the Fox News Channel were reports on Van Jones, Obama's green jobs czar, who as a San Francisco community activist signed onto conspiracy theories questioning whether the U.S. government played a role in the Sept. 11 attacks.

Some conservatives are also raising questions about a White House dinner invitation to the lead lawyer in American Civil Liberties Union lawuits that have forced the government to disclose Bush-era interrogation techniques. The lawyer was invited to an event for Ramadan, the Muslim holiday.

Even Obama's plan to address the nation's schoolchildren on Tuesday has prompted an outcry among conservative parents and GOP officials, who have accused the White House of trying to infuse "socialism" into the minds of young people.

These controversies followed earlier efforts by some conservatives to press ongoing conspiracy theories that the president was actually born overseas and is ineligible to hold office, and that his true religion is Islam--theories that some Democrats worry could be affecting the public's view of the president and his party.

Pew first identified a slippage in white support immediately following a press conference in July, when Obama took the surprising step of criticizing a white police officer for acting "stupidly" in arresting a black Harvard professor.

Still unclear is whether Obama's slide in the polls is due solely to his policies, or whether questions about his personal background or allegiances have had an effect.

During the presidential campaign last fall, the nation's economic meltdown swamped any attempts by Republicans to portray Obama as having radical associations with figures such as his former pastor, the Rev. Jeremiah A. Wright Jr. Some conservatives, such as Fox's Glenn Beck and Sean Hannity, have continued to raise such concerns.

One black congressman, Rep. Charles Rangel (D-N.Y.), was quoted last week alleging that opposition to Obama's health care policies was "a bias, a prejudice, an emotional feeling."

"Some Americans have not gotten over the fact that Obama is president of the United States. They go to sleep wondering, `How did this happen?' " Rangel said, according to the New York Post.

Democratic pollster David Beattie conducted a survey last month in one competitive congressional district that found that more than one-fourth of independents believed Obama had not proven his natural-born status. The same sentiment was expressed by nearly six in 10 Republican women--a group that Beattie said would be important for a Democratic victory.

He declined to name the district because the polling was private--but said that such questions about Obama's background seemed to be a "proxy" for voters' growing unease with Obama's ambitious agenda, which has included a potential push to create a government-sponsored health insurance plan. Surveys show that the vast majority of Americans like Obama personally, but that they are increasingly skeptical of policies that seem to expand the scope and size of government.

"We're having an economic culture war," Beattie said. "The criticisms of Obama are about the fundamental role of government in our economy."