Although there is nothing new about Republicans appealing to racist impulses in the electorate, this is typically done with dog whistles and code– “welfare queens” and calling Obama the “food stamps President.”  Trump does the same thing; but explicitly and on steroids. He also gives cover to his supporters engaging in public intimidation and/or violence.   While he remains a weak (though not quite fatally flawed) general election candidate, I agree with Jonathan Chait that his style is corrosive to democracy and politics even if he is defeated in the general election.  From Chait:

The Republican Party relies on the covert mobilization of racial resentment and nationalism. Trump, as I saw it, was bringing into the open that which had been intentionally submerged. It seemed like a containable dose of disease, too small to take over its host, but large enough to set off a counter-reaction of healthy blood cells. But the outbreak of violence this weekend suggests the disease may be spreading far wider than I believed, and infecting healthy elements of the body politic…  I remain convinced that Trump cannot win the presidency. But what I failed to account for was the possibility that his authoritarian style could degrade American politics even in defeat. There is a whiff in the air of the notion that the election will be settled in the streets — a poisonous idea that is unsafe in even the smallest doses.

Matthew Yglasias comes to a similar conclusion:

The framers of the Constitution rather sharply circumscribed the president’s authority to make and repeal legislation, making it in many respects a weaker office than the prime ministerships of more majoritarian countries. But the president and his appointees have enormous discretion over the enforcement of existing laws. Putting a leader who would condone violence against the supporters of his political opponents in charge of the federal law enforcement apparatus is frightening. Giving him the power to unilaterally issue pardons is terrifying.

There have been clear signs all year that this was the direction the Trump phenomenon was heading, but I assumed that as he got closer to the Republican nomination Trump would tone down his extreme behavior in order to demonstrate his acceptability to mainstream voters. In fact, he has done the opposite. It’s a surprising decision that has truly scary implications for how he might behave were he to actually win the presidency.

The sooner Trump’s candidacy ends the better.  In a separate piece, Yglasias makes the case for Democrats to cross over and vote for Cruz in open primaries because he is probably the only candidate who could actually overtake Trump in the delegate race.