I was hit by the "You're a bigot because the SPLC said so" argument

In debating Men's Rights with someone I was told I was a bigot because I used a term for a specific argument that was invented by someone who is loosely associated with a group that was labeled by the SPLC as a burgeoning hate group.

Now, this is obviously an extreme example because anyone who would say such a thing will not be convinced no matter what I say. But the shutting of people's ears before I speak is a major problem and was only exacerbated by the recent article from the SPLC.

So, what are some good arguments against it? And what are some good resources to direct people to?

I am not asking for how to win an argument, I am asking for ways to win people over. We should have a few responses in our chamber ready for action whenever we get hit by this because I can see it happening more often in the near future.