WASHINGTON - President Bush's push for a new immigration policy and his acknowledgment of global climate change as a serious concern won praise from presidential candidates in both parties today even as they split on partisan lines over Iraq.

Bush appealed to Congress in his State of the Union speech to give his Iraq strategy a chance to work, running into a wall of skepticism, especially from Democrats who control the House and Senate.

That response carried over into the morning talk shows, where Democratic presidential aspirants Barack Obama and Bill Richardson voiced firm opposition to Bush's troop escalation. “He has not made the case,” Obama, an Illinois senator, said on CBS' “The Early Show.”

Two Republican presidential hopefuls - Arizona Sen. John McCain and former New York Mayor Rudy Giuliani - countered that there is no choice but to give Bush's plan a chance to succeed. “It's the only game in town,” McCain said on the same program.

Giuliani, on NBC's “Today” show, said: “I believe we should give the president the support to do this.”

Bush also urged lawmakers in his speech Tuesday night to send him legislation helping more Americans afford health insurance, reduce the nation's dependence on foreign oil, overhaul immigration laws and renew his signature No Child Left Behind education program. He declared climate change a “serious challenge” but did not endorse proposals for mandatory reductions of greenhouse gas emissions.

“The idea of climate change finally passed his lips,” Obama said. “That's long overdue.”

McCain also welcomed Bush's acknowledgment, while saying “of course” the U.S. needs to go farther than Bush has proposed on the issue. “We've got to start reducing these greenhouse gas emissions before our planet is unalterably heated, and the consequences of that are catastrophic,” he said on CNN.

Richardson, the New Mexico governor, predicted Bush and the Democratic Congress will be able to work together on a comprehensive plan to control illegal immigration. McCain agreed: “We can come together on that issue.”

Bush arranged a trip to Wilmington, Del., today to plug his energy proposals at a DuPont Co. facility where scientists conduct research on the use of plants in the production of biofuels such as celluosic ethanol.

But Democrats kept the spotlight on the war, as the Senate Foreign Relations Committee took up a nonbinding measure that rejects Bush's planned troop increase as “not in the national interest of the United States.”

As is customary, Republicans cheered longer and louder than Democrats on Tuesday night when Bush walked down the middle aisle of the House chamber to deliver his annual address to Congress and the nation.

But it was the Democrats' turn to whoop it up when the president remarked he was the first chief executive to “begin the State of the Union with the words Madam Speaker.”

Rep. Nancy Pelosi, the first female House speaker, was seated next to Vice President Dick Cheney on the dais behind the president, and smiled and reached down to shake Bush's hand.

Democrats chose Sen. Jim Webb of Virginia to deliver the party's formal televised response to the speech, and the former Republican Navy secretary and Vietnam veteran responded with a blistering attack on the president, the war and the consequences.

“The president took us into this war recklessly. He disregarded warnings from the national security adviser during the first Gulf War, the chief of staff of the Army, two former commanding generals of the Central Command,” and more, Webb said.

“We are now, as a nation, held hostage to the predictable - and predicted - disarray that has followed.”

Republican leaders generally expressed support for Bush's Iraq strategy. “If we fail in Iraq, or withdraw our troops prematurely, the terrorists will follow us home. Success is our only option,” said Rep. John Boehner of Ohio.

But numerous members of the rank and file did little to hide their concern.

“To put more American personnel in harm's way without a realistic chance for success is something I'm not in favor of,” said Sen. Arlen Specter, R-Pa. “And a realistic chance for success depends upon having the Iraqis with the will and the ability to fulfill their share of the bargain, and so far they have not.”