Now really.
Where and when did "leftists" promise to be tolerant?
Sirs, if you consider tolerance to be a virtue , you may praise it and you may criticise its absense, but most of all you may provide example.
And be tolerant , even if this requires you to operate at a disadvantage.
I don't think that "the left" has special claim on any particular virtue , but neither do we on "the right" because neither of us now can inherit virtue proven in previous times even if we were there ourselves proving it.
All the past is just practice.
Virtue that counts is virtue now, the moment virtue is valuable is the present.