The second round of the presidential debate series has the candidates at a disadvantage, because they now have a new standard to live up to: the performance of their respective running mates.

Dick Cheney and Joe Lieberman gave impressive performances in the vice-presidential debate last Thursday in Kentucky, and they’ll be a hard act to follow for two reasons.

First, both were sufficiently knowledgeable to convince viewers that they’re well qualified to assume the presidency if worse comes to worst. Cheney, especially, shored up his partner’s position by proving that as veep, he’s indeed capable of understanding the issues and giving solid advice on complicated topics. That’s important because there’s a substantial bloc of voters who favor Republican parties but are not yet convinced that George W. Bush has a tight grasp on them.

Bush doesn’t really need complete mastery of the issues, of course. The same people who are advising him during his campaign could continue to advise him during his presidency, and they could be augmented by others who have proven expertise in every area he would need to address. Cheney provides that depth in several areas, including defense and petroleum policies. Still, the fact that George W’s foot lingers dangerously close to his mouth is a matter of some concern.

Lieberman is an equally valuable addition to the Democratic ticket. Like Cheney, he provides additional intellect and expertise, and he’s already proven that he’s capable of being more than a yes-man. Some analysts worried that, during the vice-presidential debate, Cheney had managed to demonstrate that Lieberman had changed his position on at least one important issue, but that’s not entirely a bad thing. An open mind near the White House could prove to be a very useful commodity, and a vice president who could passionately argue his own ideas surely would serve refine the administration’s position.As Cheney and Lieberman were demonstrating their own competence, they also managed to demonstrate something about politics: Here, in this final election of the twentieth century, a campaign can still be conducted with integrity and even dignity.

Both men made their points ably, and while they were doing it, each showed considerable respect for his opponent. There was no smirking, no sneering, and no hint that either man had forgotten basic good manners. Both Cheney and Lieberman appeared to be having fun, and debate viewers could picture themselves sitting down to the dinner table with either, or even with both at the same time.

The same cannot be said of the presidential candidates, who sometimes seem to bear each other genuine animosity. That’s worrisome. Although their politics differ, both have spent many years in politics and surely have made sufficient contributions that they should at least be considered worthy opponents.