President Bush’s top political adviser, Karl Rove, defended his boss yesterday by arguing that Mr. Bush’s slide in public opinion polls can be attributed almost entirely to public concern about the war in Iraq.

“I think the war looms over everything,” Mr. Rove said during a morning appearance at the American Enterprise Institute in Washington. “There’s no doubt about it.”

Mr. Rove said he believes most Americans are content with their economic position, but are in a “sour” mood because of the continuing violence in Iraq. “Being in the middle of a war where people turn on their television sets and see brave men and women dying is not something that makes people happy and optimistic and upbeat,” he said.

However, the veteran political strategist said he disagrees with the predictions that Republicans are certain to lose seats in Congress in November and could lose control of both chambers.

“We are going to be just fine in the fall elections,” Mr. Rove said. He said the GOP has clear stances on national security, tax policies, and federal spending restraint, which will bear up well against more vague policies advanced by the Democratic Party. “The other party seems to stand for little except obstructionism.”

One key to GOP victory, Mr. Rove said, is the basic political outlook of American voters. “Ultimately, the American people are a center-right country, who, presented with a center right party with center-right candidates, will vote center right,” he said.

Mr. Rove did not say explicitly whether he expected the military situation in Iraq to improve before the midterm election. “We will fight our way through,” he said, without elaborating.

While Mr. Rove is known for his masterful ability to analyze public opinion research, he chided journalists yesterday for being obsessed with such surveys. “I love this mania that’s just swept through American media today, which substitutes polls for coverage of substance,” he said sarcastically. “You’ll work your way through it eventually. There’s I’m sure going to be a special Betty Ford addiction for those that are addicted to regular poll numbers.”

Mr. Rove was dismissive of conservatives who believe Mr. Bush has done too little to rein in federal spending. “They’re missing the facts,” the political adviser said. He insisted that none of the spending bills signed by Mr. Bush exceeded the targets he set for them.

Mr. Rove said the narrow Republican margin in Congress makes it difficult to pass legislation that makes substantive cuts in discretionary domestic programs. “It requires a lot of energy and a lot of will and a lot of nerve and we’re pressing the issue and I’m happy to defend the record any day of the week,” he said.

Speaking to a mixed audience of public officials, lobbyists, think tank researchers, and journalists, the presidential adviser also opined on the subject of a presidential address last night, immigration. Mr. Rove conceded that nearly five years after the September 11, 2001, terrorist attacks, the border with Mexico remains an open target for terrorists seeking to enter America. “We’ve got a border that is so porous and so insecure that who knows whether that is simply an illegal immigrant looking to get a job at a landscaping company or throwing tar, or whether it’s somebody that wants to do something worse,” he said.

Mr. Rove did not explain why the Bush administration has not acted decisively to secure the border, but he insisted that more illegal crossers are being quickly deported, even to countries like China. “Illegals that we catch here who come from China, now we stand a much better chance of being to process those people rapidly and get them home,” he said.

While much of Washington is waiting for a decision from a special prosecutor about whether to seek an indictment of Mr. Rove in connection with an investigation of the alleged leak of a CIA operative’s identity, the presidential adviser brushed aside a question about the matter yesterday. He referred journalists to a statement his attorney, Robert Luskin, released last month in connection with Mr. Rove’s fifth appearance before grand juries investigating the leak.

In the statement, Mr. Luskin said the prosecutor, Patrick Fitzgerald, told Mr. Rove he is not a target of the investigation and no decision has been made about whether to charge him with a crime.