I've heard the "We need to talk to the other side, to convince them,

not dismiss them" argument.  A lot.  There is a slight problem.
There's a group calling itself 'Progressive Centrists' on FB; as you might expect solidly
Anti-2nd Amendment
Pro government healthcare control
etc.
Their response to saying something that contradicts the approved stance?  They block you.
I'm not nearly on the level of Kevin or Linoge or Thirdpower on having a pile of stuff ready to link to, and facts ready-to-hand; didn't matter.  Just for pointing out a problem with a statement* and providing a couple of links I disrupted the approved line of thought, so 'blocked!'

Friend had a link to a 'feminist' site demanding free contraception and abortions; say something outside the approved stance, they block you.

On and freakin' on.  It's hard to argue(or politely discuss if you prefer) with someone who doesn't want you to speak at all, who won't allow you to speak.

Yeah, it's their site, and they can block whoever they choose; a bit hard to take when they've been bitching that "Those people on the other side don't want to actually talk about this!"  Really?  Have you considered the idiocy of whining that when you actively prevent anyone from disturbing your echo chamber?

So most of the time I don't even try anymore.   Friend had a link to a "Why don't men speak up and do something for women?" post, and I started to respond; then I looked at the site, and passed.  Standard-issue leftist "Women good/men bad", "Government control good/private bad" crap.  At best I'd be told I don't care about women, at most they'd insult me and then block me.  Then congratulate themselves on 'running off the troll'.

Talking to the other side is fine, and I do it; when they respond to argument with emotion and screaming and such, kind of hard to have a discussion.  Like the crap after Sandy Hook: if you don't agree with them to ban everything in sight you're 'making excuses for murdering kids', you're (fill in the blank), and when you tell them off YOU suddenly are 'making this a slanging match, and I'm not participating!'  Yeah, they insult YOU, and when you show them they're full of crap YOU'RE causing the problem and they run away.  Probably to brag about 'telling that bloodthirsty gun nut off'.

Unpleasant fact is that the real gun bigots and hoplophobes you can almost never reach; they BELIEVE what they spout, and anyone who disagrees is in favor of dead kids.  How the bleeping hell can you argue with that level of disconnect from reality?

Added: From Publicola,
We have to understand what's facing us. If you think it's anything short of extinction you're mistaken. No; they're not talking about rounding us all up and putting us in the ovens (well most of them aren't at least). They're doing everything they can to wipe out our culture. 
...
They want us extinct.
Not in the physical sense, but in the cultural sense.
Yes, they do.  That's all they care about, and they won't hear anything that disagrees with that aim.  Or if they hear it, it's through their filter that proves anyone who disagrees with them wants dead kids and raped women.  How the hell do you argue with the True Believers?


*Don't you just love it when someone insists "Nobody is talking about banning guns!" and then add "Except those assault weapons nobody needs to own"?  Or, when you point to Feinstein and Schumer and Obama and Howler Cuomo stating what they want to ban, or actually passing a law, "Well, nobody NEEDS to have those!"?