it's all because of anal sex. homosexuality originally was banished by society because some dudes saw some faggots butt fucking each other back in the olden days and thought it was an indecent, lewd, perverted and fucked up sexual act, and homosexuality began to center on butt fucking. it was not so much the concept of homosexuality that was lewd but rather it was anal sex, and homosexuals were the group sponsoring anal sex. thus homosexuality was deemed not right. now in the 1970s-1980s, porn was becoming more prevalent, and a lot of centered on anal sex. anal porn was a feature of say 30% of porn, and given the sizable portion of the population exposed to porn, a still significant were exposed to anal porn. this cultural influence start to shift the public's perception of anal sex. no longer disgusting and perverted, anal sex was becoming eroticized, fetishized, and hot and somewhat accepted as an unusual and extreme yet unharmful act. thus the hate behind homosexuals faded, as people thought that what gay men did with each other was not that extreme. thus the reason behind homophobia was starting to disappear. thus the changing of political views towards allowing gay marriage and other pro homosexual activities.