This isn't exactly a new idea about open societies. See for example Karl Popper in 1945:
"Less well known is the paradox of tolerance: Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them."
https://en.wikipedia.org/wiki/Paradox_of_tolerance
But it is much more colloquially known as "live and let live."
>And I don't understand how the opposition to gay marriage is about separating families and is the equivalent of raging racists that lynch innocent people of colour. Can you explain that also?
Also, somewhat tired ground by now, but the California proposition would separated families and deprived them of the legal rights that families have. Your "lynch" analogy is a strawman, the KKK doesn't really do that these days, but it still does vile things. The KKK of today is quite equivalent in effect and practice to California's prop 8.