America will never be a "leader" for gay rights. Even if tomorrow all discrimination against LGBTs is done away with, we still wouldn't be a leader because of the over a dozen other countries that beat us to it. Canada or Spain are better candidates for leaders of gay rights than the US.
We're always last to get things right (abolishing slavery, women's rights, etc) but always the first to congratulate ourselves on how "progressive" we are as a country. It's like if a fat kid who got dead last in a race gloated after he passed the finish line how he's the fastest runner there.