Second: To what extent does greater partisan polarization correlate with greater public antipathy to politics in general? I would imagine quite a bit. My sense is that the middle of the polity has dropped out of political engagement. Polls show that people across the spectrum are fed up with the President and with Congress–but not just on partisan lines; the don’t trust the democrats to do much better. There is a great skepticism that any politicians are acting in the common good–and that just turns moderates and the marginally engaged.

The suggestions you make would only get at the margins of the problem. The blowback of years of (successful) negative campaigns and ad-hominem attacks is a polity which is either a) disengaged or b) highly angry and distrustful of the other party. Neither is a good sign for the future.