WASHINGTON - Members of the huge millennial generation, who have strongly supported President Obama in the past, have soured on him and take a skeptical view of his signature health-care law, according to a new poll from Harvard's Institute of Politics.

"Millennials have always been one of two significant parts of the Obama coalition," said John Della Volpe, the institute's polling director.

Throughout Obama's national political career, members of the millennial generation gave him a significantly higher approval rating than the rest of the population, he said.

Now, however, their views have become much more similar to the rest of the population.

"They're less different every day," Della Volpe said. "That's not helpful to chances of Democrats looking ahead to the 2014 mid-term" elections.

Obama's approval rating has fallen to 41 percent, down from 52 percent earlier this year, among members of the millennial generation, which the poll defined as Americans between the ages of 18 and 29.

The poll also found that people 18 to 24 identified less with the Democratic Party than those ages 25-29, suggesting that the strong support Democrats have enjoyed among young voters during Obama's two elections may be fading.

Among 25- to 29-year-olds, Democrats have a 16-point edge over Republicans in party identification, the poll found. But among 18- to 24-year-olds, that margin shrank to 6 points.

On the other hand, approval of congressional Republicans has now fallen to 19 percent among millennials, the poll found. Congressional Democrats got approval from 35 percent.

If it were possible, 52 percent of millennials said they would vote to recall all members of Congress, the poll found, and 47 percent said they would vote to recall Obama.

As with the population at large, most 18- to 29-year-olds do not expect to benefit from the health-care law.

The poll's margin of error was plus or minus 2.1 percentage points.