Although there's a fair bit of insight in what you say, I think it's extremely unlikely that you've grasped the essence of the problems, and indeed, your proposed solutions seem to me very likely to exacerbate the problem.

There's already a ridiculous amount of hissing going on, a very large portion of which is alienating the people the left needs to build coalitions with in order to govern.

Take the Virginia governor's race, for instance.

You should read something somewhat recent by Jonathan Haidt and try again as if you have to argue against him. Even if you disagree with every point he makes, in refuting the points you will have to cover lots of really critical ground, and your arguments will be much stronger.