Yeah, there's definitely a bit of fear, because there's no real limit I can see to how far things can go: between Antifa, fast and furious, operation choke point, all the Hillary things, everything that Google has done, de-platforming, the ramping up the rhetoric, the Obama era "let them work it out" statements to black mobs, and everything that happened with Muller, there doesn't really seem to be any line that the left (as a coaltion) will not cross. There is no real check on how much power they intend to wield, and no real sense of mercy, fairness, or tradition to constrain them.
Elections I think are increasing going to be life and death struggles, and I think the left still fully believes that demographics are destiny (which they are, within certain terms at least), and they are thus guaranteed permininate (at least for their lifetime) year rule. And once someone thinks their on the cusp of having guarenteed power, a lot of the rational for restraint in politics falls away, because there is no tict for tact, no reason to negotiate and compromise.
Politics is a game for keeps, or is being looked at as more so, and if victory now means victory forever, then there is no reason to be restrained now outside of however much present restraint aids present victory.
We already saw pretty unrestrained use of power under Obama. Whoever replaces him if the democrats win seems like they will be much less restrained than that.