The United States underestimated the difficulty of the war in Iraq, and problems there could threaten the all-volunteer military, U.S. Sen. Lindsey Graham said Monday.

South Carolina's senior senator also said if Democrats delay the nomination of Judge John Roberts to the U.S. Supreme Court, he would vote to change the Senate's rules to abolish filibusters of judicial nominees.

The Republican from Seneca offered a frank assessment of the U.S.-led war in Iraq in a speech to about 65 Beaufort County political and business leaders gathered at Wexford Plantation on Hilton Head Island.

"The good news is we're making progress," Graham said.

A draft Iraqi constitution is expected to be finished by Aug. 15. The country is to vote on whether to accept it by Oct. 15, and elections under the new constitution are scheduled for before Dec. 15.

"I've been there three times," Graham said. "In many ways, it's worse. In many ways, it's better. The security environment is much worse. We've underestimated the task that lay before us. We let the country get out of control, didn't have enough troops, and underestimated how difficult this would be. We're paying the price for that.

"But our basic idea of transforming this from a dictatorship to a democracy I think is the right idea," he said.

Graham remains optimistic about the chances for success in establishing a functioning democracy. He said every time an Iraqi leader is assassinated, someone else steps up to take his place. And whenever a police station or military installation is attacked, more recruits sign up.

American troops need to stay in Iraq until the job is finished, said Graham, a lawyer and reserve judge in the Air Force.

"The exit strategy is to leave behind a functioning democracy," he said. "If we leave prematurely, it would be the worst message we can send to the terrorists."

He noted that while the United States was established in 1776, the Constitution wasn't written until 1787.

"I don't think we're coming home any time soon," he said. "So in the short term, we're going to have to suck it up."

He noted that even though more American troops are needed to fight in Iraq, the military's recruiting isn't achieving its goals. That's why he's pushing legislation, co-sponsored by Sen. Hillary Rodham Clinton, D-N.Y., to increase benefits for military personnel and their families.

"If we don't take care of our military men and women a little bit better than we're doing today, we're going to break this all-volunteer force," he said.

Graham also defended his support of a compromise that allowed senators to continue filibusters of nominees to federal judgeships. Republicans had been considering a maneuver that would change the Senate's rules that would abolish judicial filibusters.

Graham was one of 14 senators who in May struck a deal that cleared the way for three of President Bush's nominees to be approved, while requiring that filibusters of other judicial nominees be used only in "extraordinary circumstances."

On Monday, he predicted that some groups would try to work against Roberts' nomination, but the Senate ultimately would support it.

"What's going to happen eventually with Judge Roberts is that people who are focused exclusively on abortion are going to come after him," he said.

But the Senate shouldn't allow interest groups to deter a qualified nominee, he said. If that happens, qualified judges won't be interested in rising to higher levels.

"We can't allow people who will run ads and threaten to vote against you and threaten to run against you dictate what we do," he said.

If Democrats attempt to filibuster Roberts' nomination, Graham said he would vote to abolish filibusters of judicial nominees.

In an interview, Graham said he would not run for president in 2008. Asked about speculation that he could run for vice president on the ticket with Sen. John McCain, R-Ariz., Graham said he wasn't expecting to do so.

"My plans are to seek re-election and try to be a good senator for our state, following in the footsteps of (Strom) Thurmond and (Fritz) Hollings, trying to make sure that our state gets the attention it needs and deserves," Graham said.

At a separate news conference in Beaufort, Graham said he was trying to get up to $3 million in federal money to create a land preservation program along the South Carolina coast. He intends for the federal money to match local funds, potentially helping to pay for the purchase of 770 acres in the New Riverside tract along the New River in Bluffton that would be preserved.

Final legislation that includes the land preservation program is still being worked out, and Graham expects to get less than the full amount in the end.

"I don't think we're going to hold that number" of $3 million, Graham said, "but I think we're going to hold the concept."