Ironically, I think the general definition of tolerance that is bandied about is too broad. It leads to absurdities like having to answer “well, shouldn’t you Liberals tolerate intolerance?” This is followed by a gotcha-smirk and triumphal nodding. Checkmate!
I don’t think “tolerance” should mean that we tolerate everything, and I think a better definition is in order to clarify things.
What I think we liberals, progressives, whatever, mean when we talk about tolerance is ethical toleration – tolerance of things that are not overtly harmful or ethically unjustifiable. It is the self-discipline of allowing voices that we disagree with to be heard. So, for example, it is not intolerant to move away from you if you are poking me in the eye with a stick. I can be tolerant and also avoid eye-poking. I can also be tolerant and avoid some equivalents of eye-poking.
I can be tolerant and yet not tolerate things that I think are ethically unjustifiable or harmful. In those cases, tolerant or not, I have a moral responsibility to speak out and say something, and to do what I can ethically to put a stop to what is going on. To paraphrase Oliver Wendell Holmes, I can tolerate you swinging your fist around until it connects with someone’s nose.
So, for me at least, when I write about tolerance, assume what I mean is ethical toleration. I think it is what Liberals/progressives/whatever also mean when they use that word, but you’ll have to ask them.
(Honestly, I think responsible conservatives probably buy into this in principle as well – but I’ll have to ask them.)