There are at least three important stories here, and it's hard to sort out how they interact with each other.
1) Donald Trump is a distraction from the real sources of contemporary racial injustice and inequality. The flap over the Ku Klux Klan is a classic case of denouncing the villains of the old order so as to establish one's innocence in the new order. Denouncing the Ku Klux Klan (which we should do of course!) has very little meaning because the Klan is not a key force constituting the contemporary racial order. When we denounce the Klan, we're actually not saying much of anything about our stance toward current racial injustice, any more than early twentieth segregationists who denounced slavery were implying opposition to Jim Crow. On the contrary, shutting the door on the old order helped to consolidate the new. In the same way, the question for Donald Trump and all American politicians is not whether they denounce the Klan--a group that had significant social power in the old racial order but does not have such power now--but whether they denounce the contemporary forces that undergird present-day power relations. The Klan plays a negligible role in contemporary racial injustice, but colorblind ideology is a vital support for present-day White supremacy. In American political life, we denounce the former so as to bolster the latter.
Do you denounce the forces that create and sustain racial injustice now? Do you even know what they are? By that standard, nearly all politicians of both parties fail.
Denouncing colorblindness, exclusionary zoning, and supreme court school desegregation precedents is much more meaningful and important than denouncing the Klan. Politicians across the spectrum are failing to do this. While we beat up on Trump for being a racist (and he is), there is a danger that we lose sight of the bipartisan investment in racial injustice that shows little sign of abating.
2) On the other hand, sitting quite uncomfortably next to what I have said thus far, there is a real danger that Donald Trump will bring back into the American mainstream a kind of classical racism that we haven't seen in decades. He has already brought an explicit racist populism into the national political sphere in a way we haven't seen since George Wallace. And even Wallace was never this close to winning the Democratic Party nomination. It is hard to quantify the costs of reopening the door to 1960s-style racism, but they surely include these possibilities: an uptick in hate crimes and racial violence, a degrading of our civic fabric, and a heightened sense of fear and alienation among people of color. Indeed, this last possibility is especially concerning. Imagine how it must feel to see a figure like Trump winning state after state in a major party nomination, knowing that there is no room for people who look like you in his vision of national greatness, and discerning, especially, the undercurrent of violence he threatens to unleash. This is very serious.
I'm not sure how to make sense of these two threads together--Trump as distraction from contemporary systemic racism vs Trump as resurrector of classical racism--but I think they're both happening at once and it will take a while to figure out how they relate to one another.
3) The third story is the decline and fall of the Republican Party. I can't escape the conviction that if the GOP had made a sincere effort during the Obama years to be more than a White party, it could have inoculated itself against Trump. As Adam Serwer wrote in an excellent piece months ago, Republicans have been unable to neutralize Trump because all the groups he insults are already outside the party anyway. Republican elites may deplore Trump's demagoguery, but they built a political coalition ready-made for it. Those of us who have been sounding the alarm for years can claim some sort of vindication here, but it's not particularly satisfying, especially since it's not at all clear anti-Trump Republicans will learn the lesson of the last few decades.
The roots of this go deep. At the presidential level, the GOP won the 1960s-1970s battle for southern Whites. People forget now that Democrats went hard for southern Whites too in the 1970s, and Jimmy Carter campaigned with White supremacists while feigning ignorance about it. But the GOP won that battle with the Reagan Revolution and have solidified their hold ever since, extending their reach down to every state legislature, with the key breakthrough coming in 1994 and culminating in 2010-2014. They captured southern White conservatives, but were in the process captured by them. Along the way, party elites have embraced absurd ideas about the nature of the respective partisan coalitions. There was Mitt Romney in 2012, both before and after the election, claiming that Obama won by giving "gifts" to various groups, as if Obama's strategy was different in kind from Mitt's pitch to White retirees. Last year there was the great establishment hope, Jeb Bush, proclaiming that he would not offer "free stuff" to Black voters, while refusing to say the same to the people who most need to hear it. The GOP has constructed an entire mythology of racial innocence that is unmoored from any facts or reason. Will the GOP use the occasion of Trump's rise to seriously grapple with what they've built? Or will they persist in portraying Trump as an inexplicable cancer?
More than that, will the country, will both parties, use Trump's rise to reflect on the kind of injustice we now tolerate or celebrate all around us? I'm returning now to my first point. It is well to remember that the 1890 Mississippi constitution--the crowning edifice of White supremacy after the turmoil of Reconstruction, the document that set the legal foundation for Black disfranchisement and three generations of Jim Crow oppression--was colorblind! Think of that for a moment. I bet you didn't know that Jim Crow in Mississippi, the prototypical American example of old-time racism, was established on a foundation of colorblindness. And in the decades since the civil rights movement, we have returned to colorblindness with a vengeance. We condemn the segregationists of the 1960s even as we happily live in the world they did so much to create. As the historian Joe Crespino wrote in his book on Mississippi:
In looking back over the half century since the civil rights movement, white Americans have hardly repudiated the vision of social organization advocated by Mississippi segregationists, at least if the measurement is not words but rather the actual composition of American neighborhoods and schools. Perhaps it is most accurate to say that since the 1960s, white Americans--from rural Mississippi to the most cosmopolitan communities in America--have practiced their own form of 'practical segregation.' They have rejected the ugly white supremacy of the Citizens' Council, but implicitly and explicitly they have embraced the quiet protectionism that preserved the racial and class privilege of suburban America. The closed society may have been defeated, but most American suburbs today are a world that hard-line segregationists would have little problem with.