Here's what I don't get...

If there's a rational argument for autonomy in allowing people to "govern themselves", are others rightly more certain than me in their confidence of line drawing?

For example, you can imagine the federalism argument extended:
Strong states rights. Let the majority of local people determine the legal mores and laws, and for the most part -- leave them alone. But even in Iran, hanging homosexuals is against basic human moral codes, no matter the laws. You just don't do that -- no matter what the majority thinks, and we're not even certain the silent majority there is in support.

Likewise, the Federalist Society believes in the outcome of Brown v. Board, and the passage of the Jim Crow era into time. No one argues that local choice denying personal civil rights significantly change minority lives and lifestyles. Or that anyone who wants better should save up, pick up and move to friendlier environs. The Supreme Court is right to enforce freedoms guaranteed under the Constitution in our country.

It's a strange part of democracy -- the wise overriding part, like the wisdom of one good parent or guardian.

For example, you want to encourage free elections in Gaza and Lebanon (and in EU countries, even)... but then cringe when Hamas, Hezbollah (or one of those wacky facist parties) posts a win. Like Brown or hanging homosexuals, having parties of violence representing people -- you want to override the current majority.

Sometimes the tie is immediacy -- violence, threat, death, killing off a way of life. Sometimes it's based on the majority moral code. Sometimes you wonder at the wisdom of those drawing the lines.