"Homophobia encompasses a range of negative attitudes and feelings toward homosexuality or people who are identified or perceived as being lesbian, gay, bisexual or transgender (LGBT). It can be expressed as antipathy, contempt, prejudice, aversion, or hatred, may be based on irrational fear, and is sometimes related to religious beliefs."

It's pretty clear to me that campaigning to prevent homosexuals from enjoying the same rights as heterosexuals falls under this definition.