The senator's senior policy adviser, Douglas Holtz-Eakin, says McCain made that statement in a "self-deprecating" tone of voice. He noted McCain is a former chairman of the Senate commerce committee, which has jurisdiction over topics ranging from science to sports.
"By any standard of a policymaker, he knows plenty about economics," Holtz-Eakin says.
What McCain can argue is that he's thrifty and will cut spending. He is among 47 members of Congress who eschew congressional "earmarks," or money for programs or projects back home, according to the watchdog group Citizens Against Government Waste. Obama requested about $320 million.
McCain and other Republicans have called Palin a "reformer" who has opposed what she calls Congress' "abuses of earmark spending," a reference to lawmakers' funding requests for pet projects that don't get the level of scrutiny of other federal spending.
But as mayor of Wasilla, Alaska, from 1996 to 2002, Palin hired a Washington lobbying firm that obtained nearly $27 million in federal earmarks for the community, according to Taxpayers for Common Sense, a government watchdog group.
Grover Norquist, president of the anti-tax group Americans for Tax Reform, says McCain should stress his longtime opposition to excessive spending. That way, Norquist says, he could turn Obama's mantra of a "third Bush term" on its head. "Obama is the third term of Bush overspending," Norquist says. "McCain is the antidote."
"The first fundamental, big problem that the federal government can address relative to the economy is self-discipline, getting its own spending under control," says former House majority leader Dick Armey, chairman of FreedomWorks, which promotes less government and lower taxes. "McCain understands that better than anybody."
6. Make 72 the new 60
McCain, who celebrated his 72nd birthday Friday, is not the oldest candidate seeking his first term in the White House. That was Bob Dole, trounced at 73 by President Clinton in 1996.
Ronald Reagan also was 73 when he won re-election over Walter Mondale in 1984 — an election in which he joked that he wouldn't "exploit for political purposes my opponent's youth and inexperience." McCain sometimes deflects the questions about his age by noting his good genes: His mother, Roberta, is 96.
McCain, who often says he is "older than dirt" and has "more scars than Frankenstein," needs to avoid anything that smacks of a health problem.
In May, doctors at the Mayo Clinic declared that he "enjoys excellent health and displays extraordinary energy." But McCain has had four malignant melanomas removed, including one taken from his lower left temple in 2000.
Like Reagan, McCain hopes to make his age a virtue. On the night he clinched the nomination, he said, "I may not be the youngest candidate in the race, but I am the most experienced." Obama, by contrast, is 47.
By putting the 44-year-old Palin at his side, however, McCain has made his age even more of an issue. His death or incapacitation would make her president, a position Boehner says she could "grow into."
"The debates are going to be critical," says former Republican congressman John Kasich of Ohio. "If McCain can make Obama look like his son, McCain is going to win. Obama is going to have to make McCain look like his grandfather."