WASHINGTON - White House press secretary Robert Gibbs said Wednesday he might have said things differently when he lashed out at liberals he called the "professional left" and suggested some of them should be drug tested.

But he told his daily White house briefing that he's certainly not leaving his job over the remark, as at least one Democratic congressman has suggested.

And he stuck to his line that President Barack Obama has accomplished or made great strides on key goals and promises despite criticism from some liberals that he has not done enough.

Gibbs found himself in hot water with some liberals after his remarks in an interview with "The Hill" newspaper. The spokesman said that liberals who likened Obama to former President George W. Bush on many policies should be "drug tested."

One Democratic congressman, Minnesota's Keith Ellison, suggested Gibbs resign.

Asked if he regretted his choice of words, Gibbs said, "many times I could have said thing slightly differently."

Gibbs said he hasn't talked to Obama directly about his choice of words, which he called "born out of frustration."

He said that many of Obama's campaign promises, led by the sweeping health care overhaul, have been brought to fruition, and suggested that "those are accomplishments that we all should be proud of, regardless of whether it encompasses 100 percent of what we had wanted in the beginning."

In the interview in which he dubbed some liberals the "professional left," Gibbs contended that some progressives critical of Obama wouldn't be satisfied until the Pentagon was eliminated and Canadian-style health care ushered into the U.S. Some of them wouldn't even be happy if anti-war congressman Dennis Kucinich were president, according to Gibbs.