President Bush dropped a political bomb on Democrats Thursday, calling them fearful of extreme wings of their party — particularly groups like MoveOn.org — and said they are more concerned about riling those groups than riling the U.S. military.

"Most Democrats are afraid of irritating a left-wing group like MoveOn.org," Bush said at the end news conference that touched on a number of foreign and domestic policy issues.

The president was responding to a question about an advertisement run last week by the liberal advocacy group MoveOn.org, which suggested Multinational Forces in Iraq commander Gen. David Petraeus was falsifying information about the war, under a bold headline, "General Petraeus or General Betray Us?"

"I thought the ad was disgusting," Bush told reporters in the White House briefing room.

"I was disappointed that not more leaders in the Democrat party spoke out strongly against that kind of ad, and that leads me to come to this kind of conclusion: That most Democrats are afraid of irritating a left-wing group like MoveOn.org — are more afraid of irritating them — than they are of irritating the United States military. That was a sorry deal," the president said.

"And (it's) one thing to attack me. It's another thing to attack somebody like Gen. Petraeus," Bush said.

The remarks were the strongest yet about the ad from the White House since MoveOn placed the ad in The New York Times on the same day that Petraeus was to deliver his report on military progress in Iraq to Congress.

MoveOn responded quickly to Bush's remarks.

"What's disgusting is that the president has more interest in political attacks than developing an exit strategy to get our troops out of Iraq and end this awful war," said MoveOn Executive Director Eli Pariser in a prepared statement.

"The president has no credibility on Iraq: he lied repeatedly to the American people to get us into the war. Most Americans oppose the war and want us to get out. Right now, there are about 168,000 American soldiers in Iraq, caught in the crossfire of that country's unwinnable civil war, and the president has betrayed their trust and the trust of the American people."

The ad last week struck a nerve among Republican leaders, who called on Democrats to denounce it and the group. Republican White House candidates also have been vocal on the issue, most notably Rudy Giuliani, who then asked The Times to grant him space in their pages to denounce the ad. To different degrees, Democrats have distanced themselves from the ad's message.

MoveOn, one of the most prolific Democratic campaign fundraising organizations, has since responded with more ads attacking Giuliani and Senate leadership.

The Senate on Thursday also voted 72-25 to support an amendment condemning the MoveOn ad and lending support for Petraeus. The amendment to the defense authorization bill was sponsored by Sen. John Cornyn, R-Texas.

Children's Health Care Battle

The remarks came at the end of a conference called to discuss the children's health insurance bill.

Bush had tough words for Democrats who he said were going to take health care decisions out of people's hands and put them into the hands of the government.

He called on Congress to pass his plan on the State Children's Health Insurance Plan, which would add $5 billion in spending over the next five years. A plan being pushed by Democrats, which has a chance of passing, would instead add about $35 billion in spending that would be paid for with a tobacco tax hike.

Democrats say not enough people are covered under the president's plan.

"Unfortunately, instead of working with the administration to enact this funding increase for children's health, Democrats in Congress have decided to pass a bill they know that will be vetoed," Bush said, noting that at least one Democrat has said a veto would be a "political victory."

"As if this weren't irresponsible enough, Congress is waiting until the SCHIP program is just about to expire until getting a final bill passed," Bush said.

Calling it a difference in philosophy, Bush said he would rather make sure that people have the ability to choose their own health care. He said the Democrats' bill would force some who already have private health insurance into government programs.

"We should return it to its original focus, and that is to help poor children," Bush said of the program, later adding: "I believe this is a step toward federalization of health care."

Bush then fielded questions ranging from the economy to the war in Iraq, domestic race issues, brewing international conflicts and presidential politics.

Bush said he was optimistic about the U.S. economy, despite problems in the housing and credit markets. He said he would be "pessimistic," however, if Democrats began to hike taxes.

"The fundamentals of our nation's economy are strong," Bush said.

Bush declined to discuss reports of a recent Israeli air attack on Syria. Syria reportedly has been working with North Korea and Iran to develop nuclear and chemical weapons.

"I'm not going to comment on the matter," Bush said.

The conference was the first since Bush announced last week his intention to begin bringing some troops home from Iraq. He fielded questions about Iraq, Iran and other international developments just ahead of the start of the United Nations General Assembly's new session.

The conference also came as the president faces major changes in his administration, which is looking at its last 16 months before a new president takes the helm. Bush early this week nominated retired federal judge Michael Mukasey as his choice to replace former Attorney General Alberto Gonzales.

Bush praised Agriculture Secretary Michael Johanns, who announced Thursday he is leaving his post to run for a Senate opening in his home state of Nebraska; Republican Sen. Chuck Hagel announced his retirement earlier this week.

"If it's Mike's decision and Nebraska's choice, he would make an outstanding member of the United States Senate," the president said.

FOX News' Mike Emanuel and Kelly Chernenkoff contributed to this report.