It really is remarkable how much things shifted in a relatively short amount of time, e.g.
this Pew poll shows that the country went from basically 60-30 opposing gay marriage to 60-30 supporting gay marriage between 2004 and 2017. I do think that Hollywood played a pretty major role in normalizing gay relationships among the broader public: Ellen DeGeneres famously came out as gay in 1997, and Ellen was followed by Will and Grace, a very successful show that co-starred a gay character, and Brokeback Mountain, which portrayed a gay relationship.