Their differences could not be starker.
After a quarter century at the highest levels of government, Vice President Dick Cheney epitomizes the gray Washington bureaucrat - somber, solid, unlikely to make women's hearts flutter. His challenger for White House No. 2, John Edwards, is still new to public life - just six years in the US Senate - and his stock in trade is his sunny smile and his litigator's skills of persuasion.
When the two meet up Tuesday night in Cleveland for the only vice presidential debate of Campaign 2004, the future of the free world will not be hanging in the balance. Voters vote for presidents, not vice presidents. But analysts expect viewership of the 90-minute duel to be high, nevertheless.
"It's Dr. Doom versus Huck Finn," says Cal Jillson, a political scientist at Southern Methodist University in Dallas. "Very little rides on this debate, but it's going to be enormously interesting. People will be interested to see this fairly curious matchup."
Mr. Cheney has evolved during his term as vice president. George W. Bush put him at his side four years ago to lend gravitas to the Republican ticket, an acknowledgment that Mr. Bush's Washington résumé - particularly in foreign policy - was a bit light. Now, after almost a full term in office and a trial by fire as president during Sept. 11 and two wars, Bush is running for reelection on his own record, not based on the team he will bring with him.
On the campaign trail, Cheney still represents an important voice of experience at the president's side, but he is also Bush's principal attack dog - walking right up to the line of propriety (or crossing it, in the view of Democrats) in suggesting that electing Sen. John Kerry president could make the nation more vulnerable to terrorist attack.
To base Republican voters, the red meat Cheney serves up is tasty indeed. But to other voters less sure of their leanings, he may be a liability. Halliburton, the energy firm Cheney served as CEO, has for years been a focus of controversy, both at the Securities and Exchange Commission, over Cheney's own stewardship, and now because of its Iraq war contracts. Cheney's place at the center of litigation over his White House energy task force also feeds his image of controversy, reflected in polls that show unusually high negatives for a vice president, in the 40 percent range.
Senator Edwards, only 12 years younger than Cheney but looking young enough to be his son, was selected as Senator Kerry's running mate precisely for his optimistic outlook and his ability to reach out to suburban and rural voters. In particular, his primary-season message about "two Americas" - one for the affluent and another for the rest of us - was meant to balance out Kerry's strengths in defense and foreign policy.
But in the two months since the Democratic National Convention, the North Carolina senator's most noteworthy headline came in the form of a question: Where is John Edwards? Edwards was seen as the invisible running mate, failing to defend vigorously his "client" - Kerry - against charges that he had not fully earned his Vietnam war medals, and certainly not taking the offensive against the Bush White House, in a headline-grabbing way.
Some analysts speculated that Edwards was avoiding the traditional attack-dog role of running mate to protect his reputation and political future, which may include another try at the presidency if the Kerry-Edwards ticket fails next month.
Edwards's job Tuesday will be to keep the momentum going from the first presidential debate last Thursday, which polls show Kerry won. Since Thursday, the Kerry campaign has been flying high - especially after weekend polling that puts the race back at a dead heat, after a Kerry slide of nearly two months.
Privately, some Kerry campaign officials are even worried the veep debate could halt that momentum as the next big punctuation point in the story line.
The rule of thumb in vice presidential debates is "do no harm." History shows little evidence of running mates doing their bosses much good, but some evidence that they can hurt. Perhaps one of the greatest political put-downs of all time came in 1988, when then-Sen. Dan Quayle, running mate for George Bush the elder, set himself up for Democratic veep candidate Lloyd Bentsen to intone, "Senator, you are no Jack Kennedy."
In 1992, independent candidate Ross Perot's running mate, Adm. James Stockdale, launched his debate with then-Sen. Al Gore and Vice President Quayle with this memorable opening statement: "Who am I? Why am I here?" That stymied Mr. Perot's surge in the polls.
On Tuesday night, "Edwards needs to maintain the aggressive posture that Kerry did in his debate and begin to tie the war issues to domestic issues, setting up Kerry for Friday's debate," says Ed Sarpolus, an independent pollster in Michigan. "Cheney has got to force Edwards to deal with his flip-flops, along with Kerry's."
At the very least, Mr. Sarpolus adds, viewers can assume both men now know how to behave when they are not speaking. The lasting memory of the first presidential debate will probably be the look of irritation on Bush's face as he listened to the criticisms of his Democratic challenger.