This is a real Catch-22 for gay marriage backers: Do you keep demonizing gay marriage opponents as bigoted and ignorant, and risk alienating people you might otherwise sway? Or do you lay off the vitriol, and give those who might be cowed by meaner methods the room to say “no”?

[S]trongly opposing gay marriage doesn’t mean I don’t understand why many people just as strongly favor it. I can sympathize with committed gay and lesbian couples who feel demeaned by the law’s rejection of same-sex marriage or who crave the proof of societal acceptance, the cloak of normalcy, that a marriage license would provide. I don’t regard the redefinition of marriage as a civil rights issue; nor do I buy the argument that laws barring same-sex marriage are comparable to the laws that once barred interracial marriage. But I recognize that many people - sincere and decent people - do. By my lights they are mistaken, not evil.

Why do so many same-sex marriage advocates find it so hard to see marriage traditionalists in the same light?

In a recent paper for the Heritage Foundation, Thomas Messner surveys the “naked animus’’ that was directed against supporters of Proposition 8, the California marriage amendment that voters approved last year. His meticulously footnoted study makes chilling reading, with example after example of the blacklisting, vandalism, intimidation, loss of employment, anti-religious hostility, and even death threats to which backers of Prop. 8 were subjected.

Of course not all proponents of gay marriage display such vehement intolerance. But far too many do to shrug it off as insignificant. And voters don’t have to be paranoid to wonder: If this is the kind of abuse that opponents of gay marriage can be subjected to now, how much more intolerance will dissenters face if gay marriage becomes the law?