I don't think liberals expected to have to work quite this hard to get Obama's support on so many of his campaign promises:

Reporting from Washington -- Slowly over the last few weeks, some of Barack Obama's most fervent supporters have come to an unhappy realization: The candidate who they thought was squarely on their side in policy fights is now a president who needs cajoling and persuading.

Advocates for stem cell research thought Obama would quickly sign an order to reverse former President Bush's restrictions on the science. Now they are fretting over Obama's statement that he wants to act in tandem with Congress, possibly causing a delay.

Critics of Bush's faith-based initiative thought Obama had promised to end religious discrimination among social service groups taking federal money.

But Obama, in announcing his own faith-based program this month, said only that the discrimination issue might be reviewed.

And Obama's recent moves regarding a lawsuit by detainees have left some liberal groups and Bush critics, including the American Civil Liberties Union, feeling betrayed, given that Obama was a harsh critic of Bush's detainee policies when running for office last year.

The anxiety is also being felt in the labor movement, one of Obama's most important support bases. Some union officials and their allies are frustrated that at a crucial point in negotiations over his massive stimulus package, Obama seemed to call for limits on "Buy American" provisions in the bill aimed at making sure stimulus money would be spent on U.S.-made materials.

Obama has been president for less than a month, and his liberal critics concede that the economic crisis has understandably taken the focus off their issues. But some of the issues in play were crucial to building excitement on the left and mobilizing grass-roots support for Obama's candidacy.

"He made very clear promises, and he should live up to them," said Arthur Stamoulis, director of the Oregon Fair Trade Campaign, which received an unqualified "yes" from Obama on a campaign questionnaire last year when the group asked if he would support "Buy American" requirements. "The fact that he's hedging on this is not promising. He's catering much too much to the desires of Republicans who are not going to support the change that voters wanted."

Thea Lee, policy director of the AFL-CIO, said, "We would like to have him stand more forthrightly behind the positions that he took during the campaign."