President Bush is predicting victory for Republicans in November congressional elections based on a record of promoting freedom and opportunity at home and abroad. Mr. Bush addressed Republican Party organizers amid opinion surveys showing declining approval ratings for his presidency and the Republican-led Congress.

It was an animated and upbeat President Bush who sought to rally party loyalists at a Republican National Committee gala event in Washington.

President Bush said Republicans are a party of optimism, and that under Republican leadership freedom is expanding across the globe, including in Iraq. "Free countries will lay the foundation of peace for our children and grandchildren. The enemy cannot defeat us in Iraq, and they cannot defeat us anywhere else in the world. The only way we can be defeated is if we lose our nerve, and the Republican Party will not lose its nerve," he said.

Mr. Bush promised to vigorously continue to war on terror, to keep taxes low, and deal with pressing immigration matters.

Recent polls show Mr. Bush's domestic approval ratings sinking to between 29 and 33 percent, the lowest of his presidency. According to one survey, 69-percent of Americans believe the nation is on the wrong track, and 56-percent want to see Democrats take control of Congress.

Republican Party unity is also being challenged. Opposition from Democrats to much of Mr. Bush's agenda is to be expected. But now some of the president's most conservative Republican allies on Capitol Hill are in open revolt over the administration's immigration reform plan. While they applaud the president's desire to boost border security, some strongly object to Mr. Bush's proposal to establish a guest worker program and provide a path to citizenship for millions of illegal aliens.

Wednesday, Colorado Republican Congressman Tom Tancredo had strong words for the president. "He [Bush] says, 'In order to secure the border, we have to have a guest worker program.' Well, that is purely and factually untrue, because there is no will to enforce the law. Mr. President, you show me you have the will to enforce the law, and then I will be willing to talk to you in a couple of years about some sort of guest worker idea," he said.

Another Republican congressman [Dana Rohrabacher of California] said, when it comes to immigration, the American people are, in his words, "being failed by their president."

Addressing Republican faithful late Wednesday, Mr. Bush did not respond directly to his Republican critics. But he warned his party -- and the nation -- against adopting an anti-immigrant stance. "Every immigrant who comes and works hard lifts the spirit of this country. We are a land of immigrants, and we are better for it. We always have to have confidence in our ability to be one nation under God," he said.

Administration officials say they see the immigration reform initiative as an opportunity for Mr. Bush to demonstrate leadership within his own party, and to the nation as a whole. The goal is to show results and, it is hoped, reverse declining poll numbers for Republicans as November elections draw nearer.

If current polling trends look bleak for Republicans, they also provide warning signs for Democrats. A recent survey showed 52-percent of Americans say Democrats have failed to provide contrasting alternatives to Republican initiatives.