Consider that for interracial marriage, the US was lagging international opinion substantially. E.g. in large parts of Europe there either haven't been restrictions on interracial marriage, or they have been very limited and lifted earlier, and in many countries such as the UK, there is a history of interracial marriages going back centuries (e.g. many people married Indians that came to Britain after the establishment of the East India Company). Much further resistance evaporated when European countries had an acute shortage of men following World War I, that was filled by increased immigration from own colonies.
While that may not have had a direct impact, most of the arguments against interracial marriage were thus demonstrably false, by looking to other countries, and a substantial proportion of the population of the US had come from countries where interracial marriage was legal and somewhat accepted when they emigrated.
Further, with interracial marriages, the marriages had the support of a far larger amount of churches, and legalisation happened amidst a general major push for equalisation of rights that had rallied a lot of people.
On the other hand, many of the same countries that have been liberal about interracial marriages maintained laws targeting gay people far longer, and both domestically and internationally there was not nearly the same momentum for gay rights.
Again consider the UK, where it took until 1994 for a serious attempt to reduce the age of consent for male gay sex to the same as for straight sex (from 21 to 16; bizarrely the UK did not have an age of consent for sexual acts between females). It took until 2001 for that to become reality:
The first attempt was defeated; a court challenge to the European Court of Human Right forced the UK government to try again; it was defeated twice more, and then the House of Lords dragged its feet long enough that the government was able to use Parliament Act to push it through with only the support of the House of Commons in late 2000.
As late as then, people seriously used as an argument that we needed to "protect the children".