We’re now within four hours of the second presidential debate, and the candidates are probably getting in a little rest before tonight’s town hall-style showdown in Nashville.

But for all their prep, there’s at least one big thing John McCain and Barack Obama won’t be hearing tonight—something that could well be the window into the sort of feedback that could truly influence their campaigns.

It’s Americans, talking to their televisions like they’re talking to the candidates.

Do you do it?

I do.

CNN contributor Bob Greene writes about it in a blog post here.

Greene recounts his experience last Thursday as he watched the vice presidential debate at the home of some friends. Voters talk to the TV, he says, because modern technology—television—allows them to treat the candidates “as utterly life-sized.“

That is what decades of television have done: removed whatever distance and majesty may once have accrued to the people who seek the presidency. That’s a good thing: Despite the imperfections of a system that allows voters thousands of miles removed to see the candidates walk and talk and perspire in real time, those imperfections are preferable to the built-in faults of the old way.

Need some perspective on our advantaged perspective? How about this:

Do you think Americans had any idea who they were voting for back when Martin Van Buren and James K. Polk and Zachary Taylor ran for president? It had to be like voting for a rumor—it was voting for a poster, or a handbill, or a two-week-old newspaper dispatch from a reporter far away who may or may not have gotten the quotes down correctly.

Beyond pointing out that reporters are just as susceptible to not getting the quotes down correctly now as they were in the 1800s, I have to agree.

Sometimes I read things other people write, and I think, wow.

“Voting for a rumor.“

Wow.

Here’s the irony: Here we are in the 21st century, awash with technology that includes everything from as-it-happens television coverage to computer archives reaching back a hundred years or more.

Yet some people are still casting their votes based on rumors.