Nineteen months after celebrating President Barack Obama's historic election win, disappointed liberal activists promised on Monday to turn up the political heat on a White House they said is too quick to compromise.

At an annual conference of grassroots progressives, they said the euphoria and high expectations after Obama's victory had lulled them into a false sense of security, and hopes for his success had sometimes limited their criticism.

That has changed, they said, because of what they called Obama's go-easy approach on Wall Street, ineffectual efforts to reduce high unemployment, watered-down healthcare and financial regulation reforms and escalation of the Afghanistan war.

"It is not our job to make this president or this administration comfortable. It is our job to make him do the right thing," said Darcy Burner, head of the Progressive Congress Action Fund.

"There were far too many of us who thought our job was done" after the election, she said.

Opinion polls show the surge of grassroots liberal activism that helped propel Obama and his fellow Democrats to power in 2008 has diminished, while enthusiasm has picked up among conservative Republicans eager to fight Obama's agenda and unhappy over the jobless rate and budget deficits.

Signs of the disparity were abundant at the three-day "America's Future Now!" conference, attended by more than 1,000 liberals at a Washington hotel where an exhibition hall housed just a handful of group booths and displays.

A similar conference of conservatives in Washington earlier this year drew 10,000 participants and packed a hotel ballroom with dozens of booths manned by powerful conservative lobbies like the National Rifle Association.

The contrast has contributed to expectations of big Republican gains in November elections, which could wipe out Democratic majorities in the U.S. Senate and House of Representatives.

Liberal activists said it was time to crank up the pressure on Obama, who they said had been too willing to compromise with Republicans determined to obstruct his agenda.

WAITING FOR OBAMA?

"We have to stop waiting for Obama. We have to stop taking the president's temperature. We have to stop being critics and start being actors," said Robert Borosage, co-director of the Campaign for America's Future, which sponsored the conference.

"People are strongly feeling that they need to push more. He has compromised too readily, too early," he said.

Borosage said the challenge to Democratic Senator Blanche Lincoln from the left in Tuesday's run-off election in Arkansas was a sign of a rebirth of progressive political activism.

Labor unions angry at Lincoln's reluctance to back a bill to make it easier to organize and activists unhappy with her lukewarm support of the healthcare overhaul have been heavily involved in the Arkansas race.

Some activists said high hopes for Obama made it hard to criticize him.

"There is still an extraordinary loyalty to Obama and that creates this sense of conflict," said Gloria Totten, head of the Progressive Majority, which recruits liberal political candidates at the state and local level.

But Phaedra Ellis-Lamkins, who heads an environmental activist group called Green for All, said Obama's initial acceptance of what he was told about the Gulf Coast oil spill by officials of London energy giant BP Plc was a sign of his hands-off approach with the corporate world.

"The handling of BP has been atrocious at best. I believe in the president, but I believe in the needs of the Gulf Coast residents more," she said.

Still, some activists said passage of a broad economic recovery plan, a sweeping healthcare overhaul, an increase in student aid and the looming approval of financial regulatory reforms -- even if each initiative was not perfect -- was an impressive record for a new administration.

"We have achieved much more in the last 18 months than progressives typically give ourselves credit for," said Deepak Bhargava, head of the Center for Community Change.

"The arrow of change is now headed in the right direction, even if it's not far or fast enough," he said.