Take away voting rights?

Why do people think giving everyone the right to vote is a good idea? Socrates (who is smarter than you I might point out) was derisive of democracy, calling it nothing more than mob rule. Considering how many people vote without truly knowing the issues, I think it's hurting America more than it's helping. I'd rather less people vote who actually know the issues than a great deal of idiots vote for another idiot (see: 2004 and 2000 elections). Your thoughts on this?