I'll start out easy with this blog: a politics rant that's highly derivative of other people's thinking!
In college, I took a course from John Goldsmith about a book he's writing on the intellectual history of linguistics, from its emergence as a distinct discipline to Chomsky. Goldsmith distinguishes two modes of understanding history -- rupture and continuity. In the rupture narrative, benighted scholars worked to describe language until Chomsky dispelled the darkness by introducing a computational, logical mode of understanding linguistics, sprung from his mind like Athena from Zeus's forehead. Generative grammar was not just a way of describing language, it also purported to explain the mind. Scholars either got with the program or were left by the wayside.
In the continuity story, Chomsky has built on a century of development in logic and in applying formal structure to language. He builds on a foundation rather than originating one.
An anthropologist might say both stories are true. Maybe they are. But to me, the continuity story is more true. It just seems obvious that someone's work will build on what came before.
The same goes for Trump.
Corey Robin writes that the Trump hysteria seizing liberals is ahistorical. Liberals say that Trump, with his outright racism and authoritarian tendencies, is unique, distinct in American history. To these thinkers, despite pockets of intolerance, America is getting more progressive and less intolerant with each passing year. Or at least it was, until Trump, the Great Rupturer.
Robin notes that the right have been racist nationalists obsessed with authoritarianism for some time; Trump may be obscene and uncouth, but he's not exactly novel. Robin compares Trump's presumptive AG Sessions with Bush's AG. Both are essentially racists who tried to curtail black voting rights. etc etc.
What's the damage with seeing Trumpism as a rupture?
First, accuracy. Let's try to see the world how it is, not how we would like it to be. On many of Trump's more "norm-breaking" positions, he's in line with large percentages of Americans. I hate that, but it's true! Republicans have been conceding to racists and nativists among us for years. Don't normalize Trump? Too late!
Second, it's bad politics. Clinton tried to paint Trump as outside the bounds of normal American political discourse, outside conservativism, even. Unfortunately, no one cares. Trump voters wanted someone who'd blow up the system. If he's not a typical Republican, so much the better. The system as-is simply doesn't work for people . The politically salient attack against Trump is stressing the continuity. Just like the Republicans, Trump wants to cut taxes for the rich, reduce benefits to workers, take away your healthcare, embroil the US in more expensive foreign wars. He's a president for the 1% -- not for us.
Third, it changes a discussion of values into a conversation about a person. Perhaps Trump will be impeached, perhaps he'll quit, maybe he'll lose his 2020 reelection bid and start another reality TV show. He'll certainly be termed out in 2024, unless the hysterics are right and Trump's a Mussolini. Then what? Is Trumpism over? Nah. Because there never was a "Trumpism" -- just the same old nativist hysteria and white revanchism married to the interests of big business that's the bedrock of the modern Republican party. Skull and crossbones emoji!
I think voters went for Trump because he promised them material gain. Whites will regain their rightful place, factories will reopen, your decaying town will be born again. Unfortunately, at least in his Cabinet picks, Trump appears to only be serious about the first claim.
If Democrats want to win, we need to make the case that Trump's policies cause material harm. That's clearly true for the minorities he targets. Voices of people of color should be amplified in our rhetoric on Trump, both because it's the right thing to do and because it's politically relevant. In addition, Trump will preside over the continuation of decline in wages relative to buying power, a decline in good jobs and in workers' rights. This is what you get when you vote Republican. Trump is not a unique evil because he's not unique; but he is certainly evil.
So here's another continuity in American politics: everyone's prescription for a crisis is the same as the policy preferences they already held. To Keynesians, the Great Recession meant that the government needed to deficit-spend our way out. To budget hawks, the solution is austerity. I'm no different. The reaction to Trumpism should be to double-down on social democratic priorities. We need to fight for civil rights for black people, for Latinos, for Muslims, for women, and for other targeted groups. We need to fight for expanded labor rights. And we need to fight for an expanded social safety net.
 Or they perceive it as not working. Politically, what's the difference?