The value of a town hall debate is that it forces a candidate to come face to face with people who may have passionate feelings in opposition to his own. That's a sharp departure from the cheering, sympathetic crowds that jam the campaign stops that typify a run for president.

Those campaign stops are designed to convey a scripted and well-designed image to both the live audience and anyone who watches even a brief report on television. But they don't communicate much of substance. Friday night's debate did.

When a woman asked Sen. John Kerry to give assurances that taxes wouldn't be spent on abortions, it was clear she had strong feelings on the subject. Kerry had to explain himself to her, knowing she probably would disagree with his position. Similarly, when a man asked the president why he supports the Patriot Act, which, the man said, "watered down" his rights, President Bush couldn't duck the question or look to his handlers. He had to confront the man and explain himself. These were refreshingly real moments in a race where the candidates have been fighting to keep things safe.

More than any other town hall debate setting in memory, this one served to clearly define the choices voters have in this election. Yes, there were plenty of opportunities for each candidate to resort to worn-out catch phrases and useless arguments over who has changed positions on what. The back-and-forth over the war in Iraq sounded agonizingly similar to what was heard during the first debate. But most of the questions tackled real and divisive issues that had been missing from both campaigns.

One of these confronted the president's own sense of fiscal restraint, asking why he hadn't vetoed a single spending bill despite the expanding deficit. Another asked Kerry how he could be serious about cutting the cost of health care when he chose a running mate who, as a trial lawyer, has earned millions by filing lawsuits that run up the cost of medical procedures.

One man got Kerry to look into the camera and make a pledge, reminiscent of the first President Bush's "Read my lips" promise, that he would not raise taxes on anyone earning less than $200,000 a year. Another probed the president on his environmental record.

The lesson of the first debate was that demeanor counts as much as anything. Pundits said Kerry won points in that one just by looking presidential. This time, it's hard to tell who won the image war. But for undecided voters more interested in substance than image, this was the debate that gave them the information they can use to make a choice.