Those who insist that gay people are second-class human beings and don't deserve equal rights are contributing to this...

A young gay man was bashed in Nice, France, after the anti-gay marriage forces threatened to respond with violence if marriage equality passed there.  They are fueling homophobia there.

For some, if you don't think someone is your equal, then it is easy to justify whatever you want to do to them, as Jews, women, and other minorities have experienced for ages.