Democratic candidate Barack Obama razzed John McCain on Saturday over U.S. Vice-President Dick Cheney's endorsement of the Republican presidential candidate.

"I'd like to congratulate Sen. McCain on this endorsement, because he really earned it. That endorsement didn't come easy," Obama said at a Colorado rally Saturday.

He said that Cheney "knows that with John McCain, you get a twofer: George Bush's economic policy and Dick Cheney's foreign policy. And that is a risk the American people cannot afford to take.

Cheney made the endorsement at a Wyoming rally.

"This year, of course, I'm not on the ballot, so I am here ... not to vote for me, but I want to join daughter Liz, who is with me today, join us in casting ... our ballots for John McCain and Sarah Palin," Cheney said.

Dems nervous

Despite polls suggesting Obama is on the brink of a historic landslide win, many Democrats remain nervous that McCain could pull off an upset.

Democrats don't need a long memory to remember the traumatic losses for their party to George W. Bush in both 2000 and 2004.

"We are witnessing, I believe, probably one of the greatest comebacks that you've seen since John McCain won the primary," Rick Davis, McCain's campaign manager, said Friday.

But polls from numerous sources and non-partisan political watchers say otherwise.

"At this point, John McCain probably can't win without divine intervention," Charlie Cook, a respected Washington journalist who specializes in electoral forecasts, wrote Saturday in his National Journal column.

McCain spent much of Saturday in Virginia, a Republican stronghold, where voters have chosen GOP presidential candidates for the past 40 years.

But Obama has dramatically broken through in the state. Real Clear Politics' poll of polls has the Democrat ahead of his opponent by six points.

McCain told supporters that Obama's agenda "apparently ... starts with lowering our defenses and raising our taxes."

He said that while Obama was "running for redistributor in chief, I'm running for commander in chief."

McCain also acknowledged his underdog status.

"We're a few points down but we're coming back," he said. "I'm not afraid of the fight, I'm ready for it and you're going to fight with me."

Obama held attend rallies in Nevada, and then Colorado and Missouri, while his running mate, Joe Biden, took part in rallies in Evansville, Ind., as well as two others in Ohio.

All of the states the Democratic candidates are visiting went Republican in 2004.

In Colorado and Nevada, the polls show that Obama is holding a lead over his opponent, Republican candidate John McCain.

In Missouri, Obama has trailed McCain by three percentage points in two recent polls.

At present, Obama is leading in the polls coming out of Ohio, while he is considered to be in a dead heat with McCain in Indiana.

McCain had rallies in Newport News and Springfield, Va., as well as one in Pennsylvania on Saturday.

Pennsylvania, a traditionally Democratic state that McCain almost certainly needs in order to win the election, has been the focus for much of the Republican campaign in the final week.

McCain has trailed Obama by between four and eight points in recent polls in the state.

McCain will also make an appearance on Saturday Night Live, following in the footsteps of his running mate, Sarah Palin, who appeared on the long-running comedy program in October.

The state of Virginia, on the other hand, is considered a Republican stronghold, with voters having voted for Grand Old Party presidential candidates for the past 40 years.

McCain's running mate, Sarah Palin, was scheduled to attend three Florida rallies in New Port Richey, Polk City and Ocala, as well as two others in Raleigh, N.C., and Glen Allen, Va.

Obama has led Florida in recent polls, but the race is considered tight in the state that decided the controversial 2000 election that brought Bush to office. The race in North Carolina is considered close as well.

Economic issues

University of Toronto professor Arnd Jurgensen told CTV Newsnet Saturday he thought it was key for both candidates to focus on the economy in their remaining public appearances before the election.

"I think that the dominant thing for them to concentrate on and the thing that seems to be on the minds of most voters is the economy," he said.

"Foreign policy issues, as important as they are, seem to have taken a back seat to the real concerns that most people have about paying their bills, about maintaining their jobs, about the market."

Jurgensen said he thought Obama was likely ahead in the polls because of "the general perception that he is stronger on the economy."

Both campaigns were hit with mild "November surprises" on Saturday.

The Associated Press reported that Obama's aunt had been living illegally in the U.S. for the past four years.

The report said Zeituni Onyango, 52, the half sister of Obama's late father and a Kenyan citizen, was ordered to leave the U.S. after her request for asylum was turned down in 2004.

As for the McCain camp, Palin was the victim of a prank call from a Montreal comedy duo, who spoke to the Alaskan Governor claiming to be French President Nicolas Sarkozy.

In the six-minute chat, Palin tells "Sarkozy" that she might run for president in eight years and she would like to go hunting with him.

The comedy duo, known as the Masked Avengers, gave Palin a few outs during the conversation, such as identifying the Canadian prime Minister as singer Stef Carse.

With files from The Canadian Press