I'm a lefty, and I would never do or propose one of the things you claim lefties would do
I believe that more speech is always the solution. Let ideas compete equally out in the open without censor regardless of how revolting some may find some speech. After all, it is only unpopular opinions that need protecting. Nobody tries to suppress speech they agree with.
If one's ideas and speech can only gain acceptance by silencing/suppressing others' ideas and speech, then one should re-examine and re-evaluate their own ideas and speech, for that is where the problem lies.
If what you say is true then carry on, Sir, whether we may agree or not. If I may ask a favor, please have a heart-to-heart with the US Left. Sad to say, they are currently not only harming themselves but the US as well with the tactics I outlined above, which are just a fraction of the things they discredit themselves with without help of opposition.
Hell, I really don't want either faction to gain too much power. That leads to tyranny. However, the US Left has swung the pendulum quite a ways Left in the US and I fear the counter-swing, of which Trump could be just the beginning. That the pendulum has swung so far Left in the US (by US standards) is what's driven extreme political views, opinions, and policies from both sides.
A far-Right fascist authoritarian regime and a far-Left socialist authoritarian regime are nearly indistinguishable from the general populations' viewpoint.