Thirty-nine percent of them claim that they are looking toward the debates as a time to make their decision. Americans have a lot of unanswered questions about both candidates, and they intend to use the debates as a time to resolve some of them. Like many claims about televised politics, this claim is at best a half-truth. There is no precise set of standards for this judgment, which is why it is partly a visceral reaction and is colored by partisanship-loyal Democrats and Republicans can usually convince themselves that their party's nominee meets the test. But it's a real test nonetheless.
Voters expect a presidential candidate to have the characteristics they admire in a president.
It's a critical test, but it's also an inexact one, which is a reason why most candidates pass it. If he had been running for president and not vice president in 1988, Dan Quayle would have been among the few to fail. Squaring off against Lloyd Bentsen, Quayle was widely perceived by viewers to lack the intellectual agility required of a president. Ross Perot in 1992 also failed the test, even though his participation in the debates did strengthen his position in the polls. Viewers found in Perot an outlet for their dissatisfaction with the major parties, but they also concluded that Perot was not fully fit for the presidency.