Loving v. Virginia served as a landmark case that overturned the Racial Integrity act of 1924, under the basis of violating the Fourteenth Amendment and would serve as precedent and reasoning of allowing same-sex marriage. Something like that, though your thesis was pretty well on its own I commend you.

Have you thought about connecting it to other cases that involve laws being overridden by privacy issues like sodomy laws (Lawrence v Texas) and how it impacted views on homosexuality?

Also i think it would be a difficult task to show that Loving v Virginia is responsible for the decline in white supremacy and tolerate of marriage. It is a common mistakes for historians, such as yourself, to devote a radical change in society to one event. Instead you should look as change as a process that takes time.

If you are really looking to see this cases impact on current perceptions of marriage, you should look at more relevant cases that were decide today like Obergefell v. Hodges, United Sates v Windsor, Bake v Nielson. So looking at a hisorical progression of legal though on mariage is also a good direction for you. Hope this helps