Republican candidate John McCain today questioned Barack Obama's readiness for the White House as his Democratic rival planned a prime-time television appeal tonight.
Mr McCain kicked off a tour of the must-win state of Florida by warning that Mr Obama would be bad news for small businesses and workers, and by casting doubt on the Illinois senator's judgment and ability to handle a security crisis.
"The question is whether this is a man who has what it takes to protect America from Osama bin Laden, al-Qaeda, and other grave threats in the world," the Arizona said after meeting with national security advisers in Tampa six days before Tuesday's election.
"And he has given you no reason to answer in the affirmative," he said.
Earlier, Mr McCain renewed his charge that his rival's plans to raise taxes on those making more than $250,000 would hurt small businesses and accused Mr Obama of wanting to redistribute the nation's wealth as "Redistributor in Chief."
"Senator Obama is running to spread the wealth. I'm running to create more wealth. Senator Obama is running to punish the successful. I'm running to make everyone successful," Mr McCain told a Miami rally.
But Mr Obama, who would raise taxes on those making more than $250,000 and cut taxes for lower- and middle-income workers, said Mr McCain's economic policies would be bad news for the middle class and would mean more of the Republican approach followed by President George W. Bush.
"He's spending these last few days calling me every name in the book. I'm sorry to see my opponent sink so low," Mr Obama told about 28,000 supporters in Raleigh, North Carolina.
"By the end of the week, he'll be accusing me of being a secret communist because I shared my toys in kindergarten," he said before heading to Florida for his own campaign events.
"So let's cut through the negative ads and the phony attacks - under John McCain, the middle class will watch wealth get favoured over work, jobs get shipped overseas, and the cost of health care and college go through the roof."
Mr McCain is struggling to overtake Obama's lead in national polls and to defend about a dozen key battleground states won by Bush in 2004, with Florida and its 27 electoral votes leading the list.
A Reuters/C-Span/Zogby poll showed Obama with a five-point national lead on Mr McCain. A blizzard of recent national polls give the Democrat a national lead ranging from two points to 15 points.
Mr Obama will make his first joint campaign appearance with former President Bill Clinton at a late-night rally in Orlando after an expensive prime-time television address on three networks.
Mr Obama, whose fundraising juggernaut has broken all records and allowed him to blanket battleground states with ads, has purchased 30 minutes of time on CBS, NBC and Fox on Wednesday night for an extended pitch on his economic plans. The ad costs about $1 million for each network.
Mr Obama has surged in the last month as the Wall Street economic crisis hit, with polls showing voters prefer his approach to turning around the economy.
Mr McCain countered with an advertisement expanding on his theme that his rival is too inexperienced to trust in the Oval Office, and he released another spot on Wednesday expanding on the theme.
Mr McCain also renewed his call for the Los Angeles Timesto release a videotape of a 2003 banquet where Obama spoke of his friendship with Rashid Khalidi, a leading Palestinian scholar and activist.
Also present was William Ayers, a former 1960s radical who Mr Obama served with on a community board in Chicago.
The Timesreported on the contents of the tape in an April 2008 story about Mr Obama's ties with Palestinians and Jews but says it cannot release the tape because it was obtained from a source on the promise it would not be released to the public.
A campaign official said Mr Obama's ad would include a video montage, footage of ordinary Americans telling their stories and some live portions of Mr the candidate.
The ad, which airs at 8pm EDT (0000 GMT), coincides with the anniversary of the October 29th, 1929, "Black Tuesday" stock market crash that ushered in the Great Depression.
The cost has been estimated at close to $1 million for each major network slot and reflects the huge cash advantage the Democratic candidate has over McCain.
The "infomercial" is a throwback to a political advertising strategy common in the 1950s and 1960s, and it marks the first such paid national political telecast since Ross Perot ran a series during his independent bid for president in 1992.
Mr Obama will also appear on the Comedy Central network's popular The Daily Show with Jon Stewarttoday, reaching out to younger voters for whom the topical humour show has become a major source of news and ironic commentary.
His Republican rival John McCain plans to appear on CNN's Larry King Live, hoping to woo viewers with his own vision of the country's future.
Reuters