ST. PAUL, Minn. – President Bush led a convention chorus of praise for John McCain Tuesday night, hailing him as “ready to lead this nation” and a courageous candidate who risked his White House ambitions to support an unpopular Iraq war. Republicans rallied forcefully behind vice presidential running mate Sarah Palin in the face of fresh controversy.

Barack Obama drew criticism from the convention podium when Senator Joseph Lieberman said the Democratic presidential candidate voted to cut off funding “for our troops on the ground” in Iraq last year. By contrast, Lieberman, who was the Democrats’ vice presidential nominee in 2000, said McCain had the courage “to stand against the tide of public opinion.”

McCain was in Pennsylvania and Ohio during the day, campaigning his way into the convention city where the 72-year-old Arizona senator will deliver his formal acceptance speech on Thursday night.

Hundreds of miles to the west in St. Paul, about two dozen men who were Vietnam prisoners with him a generation ago sparked chants of “USA, USA” when they were introduced to the delegates.

Bush reprised the national security themes that propelled him to a second term as he spoke – briefly – from the White House. “We need a president who understands the lessons of Sept. 11, 2001,” he said in prepared remarks. “That to protect America, we must stay on offense, stop attacks before they happen and not wait to be hit again. The man we need is John McCain.”

Inside the convention hall, former Tennessee Senator Fred Thompson delivered a strong defense of Palin. He said the Alaska governor, was “from a small town, with small town values, but that’s not good enough for those folks who are attacking her and her family.”

He said McCain’s decision to place her on the ticket “has the other side and their friends in the media in a state of panic.”

Other Republicans – delegates and luminaries alike – defended Palin, who disclosed on Monday that her 17-year-old unmarried daughter is pregnant. In addition, a lawyer has been hired to represent the governor in an ethics-related controversy back home in Alaska.

Conservatives, slow to warm to McCain even after he clinched the nomination last spring, were particularly supportive.

“I haven’t seen anything that comes out about her that in any way troubles me or shakes my confidence in her,” said former Arkansas Governor Mike Huckabee, who ran unsuccessfully for the party’s presidential nomination this year.

“All it has done for me is say she is a human person with a real family.”

And Ron Nehring, chairman of the California state party, said video footage of Palin on a firing range was helping her cause.

“The reports I’m getting back is that every time they show that footage we get 1,000 precinct walkers from the NRA,” he told members of his state’s delegation, to laughter. “She cuts taxes and shoots moose. That’s Governor Palin,” Nehring said.

Thompson jabbed at Obama on abortion, as well.-

“We need a president who doesn’t think that the protection of the unborn or a newly born baby is above his pay grade,” he said in prepared remarks, referring to a recent episode in which McCain’s White House rival said it was “above my pay grade” to decide the point at which an unborn child is entitled to rights.

There were indications that Republicans thought they could turn Palin-related controversy to McCain’s gain. Officials said Levi Johnston, the 18-year-old father of the baby Bristol Palin is expecting, was en route to the convention from his home in Wasilla, Alaska.

McCain’s wife, Cindy, took in the evening program from a VIP box. So, too, former President George H.W. Bush, accompanied by his wife Barbara.

Bush, with his approval ratings in the 30-percent range, was relegated to a relatively minor role at the convention of a party that has twice nominated him to the White House. The president scrapped a planned Monday night speech because of the threat Hurricane Gustav posed to New Orleans. With polls making it clear the nation is ready for a change, the McCain campaign indicated there was no reason for him to make the trip to St. Paul.

The president referred to the years of torture McCain endured as a prisoner of war. Then Bush added, “If the Hanoi Hilton could not break John McCain’s resolve to do what is best for his country, you can be sure the angry left never will.”

“As president he will stand up to the high tax crowd in Congress … and lift the ban for drilling on America’s offshore oil,” Bush added.