repetition.

You don't need to bash skinny people to say bigger people are beautiful.
You don't need to bash men to promote women's rights.
You don't need to bash white people to promote racial equality.
You don't need to bash a certain genre of music to promote another.
You don't need to bash straight people to promote gay rights.

You don't need to bash anyone to advocate your opinion.

I'm posting this again, so I remember this better. This is the most accurate thing I've ever read.