I keep hearing how important it is for everyone to vote.

Let me be politically incorrect and say that maybe some people shouldn't vote.

I know I'm swimming against the tide. Get-out the-vote groups now register young people at rock concerts. HeadCount cofounder Andy Bernstein told me: "We registered over a 100,000 people. It is so imperative that this generation's voice is heard."

But wait. Is that really a good idea? Many kids don't know much. At a HeadCount concert, "20/20" asked some future voters, "How many senators are there?" One said 12, another 16, and another 64. One girl guessed, "50 per state."

Most kids didn't know what Roe v. Wade was about. "Roe vs. Wayne?" asked one. "Segregation, maybe?" "Where we declared bankruptcy?"

Headcount's Marc Brownstein concedes, "there's a lot of uninformed voters out there." But he argued:

"Democracy is not about taking the most educated portion of the society and having them decide who's going to run the entire society. Democracy is about every individual having a voice."

I suggested that when people don't know anything, maybe it's their civic duty not to vote.

"It's an argument that really, really smacks against everything we hold dear as Americans," Bernstein replied.

Maybe it was unfair to pick on kids at a rock concert. I went to Washington, D.C., and showed people pictures of prominent Americans. I'm happy to say that everyone recognized Barack Obama and John McCain.

But only about half recognized Sarah Palin, and most didn't know Joe Biden. Few people recognized Supreme Court Justice Ruth Bader Ginsburg, but everyone quickly identified TV's Judge Judy.

Economist Bryan Caplan, author of "The Myth of the Rational Voter", points out, "the public's knowledge of politics is shockingly low."

He scoffs at the idea that "it's everyone's civic duty to vote."

"This is very much like saying, it's our civic duty to give surgery advice," Caplan said. "We like to think that political issues are much less complicated than brain surgery, but many of them are pretty hard. If someone doesn't know what he's talking about, it really is better if they say, look, I'm going to leave this in wiser hands."

Isn't it elitist to say only some people should vote?

"Is it elitist to say only some people should do brain surgery? If you don't know what you're doing, you are not doing the country a favor by voting."

My ABC "20/20" segment about this enraged some viewers. Continued...