Washington - The race for the US presidency was entering the backstretch Monday as Democrat Barack Obama pushed to keep Republican John McCain on the defensive in states long regarded as Republican strongholds - like Virginia and Florida.

Senator Obama was to deliver a speech in the hotly contested manufacturing-intensive Rust Belt state of Ohio that his campaign called his "closing argument."

A campaign statement said the 47-year-old senator would continue the argument that Senator McCain represents four more years of US President George W Bush's policies and that a vote on November 4 for Obama was a choice for "an economy that rewards work and creates new jobs and fuels prosperity from the bottom up."

Voters "can choose hope over fear, unity over division and the promise of change over the power of the status quo," the campaign said in a statement, summarizing the speech.

McCain and his vice presidential candidate, Alaska Governor Sarah Palin, were expected to campaign in Ohio, Florida, Virginia, North Carolina, Indiana and Missouri - states captured solidly by Bush in 2000 and 2004 but where the race is close this year.

Resignation was building among many Republicans that McCain could no longer pull out a victory.

"Any serious Republican has to ask, 'How did we get into this mess?'" Newt Gingrich, who engineered the Republicans' 1994 takeover of Congress, was quoted as saying by The New York Times.

"It's not where we should be, and it's not where we had to be," Gingrich said. "This was not bad luck."

Obama, seeking to become the country's first black president, was expected this week to make his ninth appearance in Virginia since the general election campaign began in late August. He hopes to turn the state Democratic for the first time since 1964 when president Lyndon Johnson took the heart of the Old South.

Polls showed Obama leading McCain by an average of 7 percentage points in Virginia, realclearpolitics. com reported.

An estimated 20,000 Obama volunteers were canvassing Virginia this week and making arrangements to transport voters to polls, NBC television reported.

Last week, the Obama campaign sent out a call for more than 800,000 volunteers nationwide, a testament to the strong organizational abilities of his campaign, which has also raised a record 600 million dollars.

Obama was also to return to Florida for part of two days this week and campaign in Ohio, Pennsylvania and North Carolina.

McCain has said he is determined to reclaim Pennsylvania from Obama's 11-percentage-point lead in the last week of the campaign after white male blue-collar workers in the state preferred Obama's Democratic rival Senator Hillary Clinton during the primaries.

Obama has purchased 30-minute, primetime television spots Wednesday on several major networks to emphasize his closing arguments, an unprecedented expenditure of millions of dollars for a presidential campaign.

In the McCain camp, there were reports of disarray. The insider online newspaper Politico. com, citing four Republicans close to Palin, reported that the governor is going against instructions from the McCain campaign.

She has bristled over revelations that the campaign spent 150,000 dollars on her upscale wardrobe, reports that have eroded the homespun housewife-hockey-mom image she has cultivated.

Defending herself against the reports at a campaign rally Sunday, Palin touched the earrings she was wearing, saying they had been beaded by her mother-in-law, an ethnic Inuit.

She said her wedding ring was a 35-dollar item "I bought myself." The pink top she was wearing, she said, she had bought at an Anchorage thrift shop where she usually shops.

Politico. com said Palin supporters were bracing for McCain and the party to blame her if the campaign fails and "shred her" afterward.

Palin, who served as a small-town mayor and two years as governor of Alaska, is seen by many centrist Republicans and the prized independent voters as unprepared for the presidency should something happen to McCain, who is 72 and would be the country's oldest president ever elected to a first term.

McCain nominated Palin after meeting her once or twice in a gesture intended to cultivate support among social conservatives who are skeptical of the former Navy pilot.

That decision was cited as one reason by retired general and former secretary of state Colin Powell, one of the Republican Party's top stars, for endorsing Obama last week. (dpa)