Federal spending was the topic and Democratic presidential hopeful Dennis Kucinich (search) came prepared with a pie chart to argue his point about a bloated Pentagon budget.

But although many listened to Tuesday's presidential debate, few could see the Ohio congressman's prop.

The debate was broadcast only on National Public Radio.

As Kucinich challenged Democratic front-runner Howard Dean (search) for refusing to acknowledge that the Pentagon budget (search) needs to be cut, debate moderator Neal Conan of NPR interrupted.

"Congressman Kucinich is holding up a pie chart, which is not truly effective on radio," Conan told his listeners.

Kucinich was not deterred.

"Well, it's effective if Howard can see it," he replied.