The Fox Guarding the Hen House

I believe in liberal democracy, which is a democracy that worries about the tyranny of the majority, but it is the majority itself that must draw the lines. - Supreme Court Justice Antonin Scalia (found on CBSnews.com)

Just one question. If democracy is protecting the minority from the tyranny of the majority, and the majority is making all the rules and drawing all the lines, does it really work?