Witcover: A vice-presidential debate of note

Vice presidents usually gain the national spotlight only upon the death of a president, as has occurred eight times in the last 171 years, or upon his resignation, which has happened once. But the current veep, Joe Biden, suddenly finds himself in its glare as a result of a much less calamitous event.

President Obama's unanticipated weak debate performance against Mitt Romney has thrust Biden into the role of firefighter, sent to extinguish the flames of revived Republican hopes in tomorrow night's debate against Romney running mate Paul Ryan.

It will be Biden's task to rally Democratic spirits with a forceful performance that can show his boss the way to recoup from the earlier reprieve Obama handed Romney by giving him a free ride on his most vulnerable positions in the presidential race.

Because Biden will be debating Ryan, not Romney, the vice president will be limited at best to bank shots off Ryan, questioning the credibility of the Romney-Ryan ticket on its late-campaign claim to have concern for middle-class Americans.

Romney in the Denver debate sought to pivot toward that more moderate posture. He finally defended his Massachusetts health-care bill, had a good word for Wall Street regulation and insisted he will not come down on the side of the wealthy on tax policy.

All this was an obvious effort to counter the condemnation he drew in his closed-door dismissal of "the 47 percent of Americans" who don't pay federal income taxes and who shun responsibility for their own welfare. Biden, unlike Obama in Denver, is not likely to let that Romney pivot go uncommented on in his debate with Ryan.

Biden must also deal directly with Ryan's own "roadmap" for economic recovery, which is considerably harsher on the poor and the middle class than Romney's now-softened position in the hope of courting undecided independent and disenchanted Democratic voters.

Romney has been firm in denying that Ryan's plan, which originally included such provisions as partial privatization of Social Security and deep cuts in the social safety net for the sake of deficit reduction, is his plan. Biden has an opportunity in tomorrow's debate to ask where the Romney-Ryan ticket really stands on its newly declared devotion to the middle class.

Ryan boasts of his small-town roots in Janesville, Wis., but Biden has made a career of being the kid from coal town Scranton, Pa. He is the self-proclaimed champion of the middle class who conspicuously speaks its language. We're likely to hear as much about growing up in it from Biden as we will hear well-rehearsed statistics from wonky Ryan on how federal spending is taking America to the poorhouse.

Ryan has said he expects Biden to fire a cannonball at him from the start. And many Republicans hope that the famously loquacious Joe from Delaware will talk himself into trouble with one of his celebrated verbal gaffes, or just exhaust the audience. But Biden's recent debate history, in his failed 2008 primary bid for the Democratic presidential nomination and in his subsequent encounter with Sarah Palin, showed him to be a controlled and effective combatant.

Whatever the outcome of the Biden-Ryan event, it will remain for Obama himself to make up for his own shortcomings against Romney when they meet a second time five nights later, in the more freewheeling town-meeting debate format. It is incumbent on Biden, however, not to inject any new element or issue that might detract Obama from the task that essentially was of his own making in failing to take the argument more aggressively to Romney the first time around.

The 1980 putdown of veep nominee Dan Quayle, "You're no Jack Kennedy," is the most memorable line of any vice-presidential debate, but it did not cost the senior George Bush the presidency. More damaging might have been running mate Bob Dole's harangue on "Democrat wars" against Walter Mondale in 1976, which may well have hurt President Gerald Ford's chances for a term in his own right.

In the end, the observation of Democratic strategist Donna Brazile -- that a running mate must adhere to the old physicians' oath, "First, do no harm" -- does apply to both participants in vice-presidential debates.

Jules Witcover's latest book is "Joe Biden: A Life of Trial and Redemption"