Gay marriage is one of the least important big issues in American politics.
I'm guessing you're not LGBT.
Yep, just like 98% of the population.
That number is arguable, but we won't get into that. Perhaps it is easy to be dismissive since it doesn't directly affect you. As someone who is LGBT, I find your statement insensitive.
Let's imagine we're in the 1960's. How does this sound?
I'm well aware that there is not an accurate census of the true gay population, but I am fairly confident that the number of African-Americans dwarfs it. Regardless, I probably would have considered interracial marriage a fairly insignificant issue in the 1960s compared to the Soviet Union, Vietnam, Medicare, Voting Rights, and racially-motivated violence.
A better comparison might be the size of the gay population to the number of people who want to marry someone of a different race.