Marriage ceases to be simply a social convention and religious institution as soon as the government starts officially recognizing it and affording people rights and privileges based on it. As soon as the government tells me I cannot marry another consenting adult, whether due to race, religion, or gender, then they are not treating people equally.
But that's the subject of a gay marriage thread, which is a forbidden topic since folks here can't handle it in a mature and civil fashion. If you want to discuss it for the (likely) short life of the thread, go start it...I've reached my quota, I think.
As for calling illegal immigrants "invaders," I'd not call that hate. It's somewhat excessive rhetoric meant to drum up emotions in the weak minded, but not hate speech.
I think what WildAlaska is talking about is the general impression society gets of firearms enthusiasts that we're all a bunch of rednecks and/or racists...generally the latter. And based on my experiences at ranges (of the less official type) when there are no minorities around, unfortunately they're all too often right. I think he means that maybe we should start excluding the folks who think that certain words that start with "N" are perfectly acceptable as long as no black folks are around (or sometimes even if they are). Or who think giving blacks and women the vote was a mistake, a wrongful usurpation of power by the federal government, and something best left to the states. You know, the ones who don't really think slavery was an objectively bad thing.
Because like it or not, defending the unrestricted (or even the moderately restricted) firearms rights of a bunch of mouth-breathing racist homophobic misogynist rednecks is a losing proposition. I mean, if they were just homophobic, or just racist, or just misogynist maybe we'd have a chance. Well, maybe not with that last one...they outnumber us, you know. But no, it seems like a large number of firearms enthusiasts (and definitely when taken as a group) feel the need to piss off every group that isn't a white Christian male. And by embracing and including them, we make our cause almost indefensible.
Of course, the question (and the problem) is whether or not these people are actually just a fringe minority of the firearms community or whether they actually make up the bulk of it.