As voters begin to shift out of the identity politics / culture war paradigm of the last generation or so, and back into one about political economy, anti-Establishment candidates like Donald Trump and Bernie Sanders are exceeding everyone's expectations.
In contrast to the Democrats' side, the rise of populism has been unlimited among the Republican side, because their form of identity politics -- evangelical Christianity -- is a form of achieved status rather than ascribed status. That is, they aren't born into their identity group, or otherwise drafted into it involuntarily. They deliberately choose to join it, usually with that choice being front and center -- they had a "born-again" experience during their own lifetimes, not that they're just going along with whatever their parents went along with.
With ascribed status, the person's membership is beyond their control, such as racial or ethnic group, sex, homosexuality, and so on. These kinds of identity groups make up the identity politics crowd among Democrats.
Because membership in the evangelical identity group stems from a deliberate personal choice, it is hard for them to argue that they are being treated unfairly as a group, and therefore harder for them to nurse a grudge and form an identity politics agenda. In the public's mind, evangelicals bear the consequences of their actions, namely choosing to belong to a group with less-than-popular beliefs about how society ought to be. If, on the other hand, someone is treated on account of belonging to a group that's beyond their control, it's more likely to strike the mind as unfair.
So, the average person is OK with excluding evangelicals from influencing school policy, because they could choose to change their beliefs to align with the mainstream, but are sticking to their guns. For the same reason, and on the other side of the political spectrum, the average person would be OK with excluding Communists or anarchists. It is not so much the people, or the identity, that is being targeted for exclusion, but the beliefs that its members choose to base their identity on.
It's the other way around with ascribed status. The average person would not be OK with excluding blacks or women from influencing school policy, because they can't change being black or being a woman, in order to satisfy the gatekeepers and wind up on the school board after all. Here, it would seem to be the person or identity themselves that were being targeted, and not just a set of views.
Therefore, blacks, women, and gays will be more likely to play identity politics motivated by the belief that they're being treated unfairly because of belonging to a group that they can't change. Evangelicals may think they're being treated unfairly, but they don't get as fiery about the unfairness aspect because they realize that they're not being discriminated against for something beyond their control. Fundamentally, they are just another ideological group. They may be angry that their ideology is being excluded in favor of a different, opposed ideology -- but not because of something they can't help.
In short, when identity is innate, it fires up identity politics to a much more fierce and stubborn game of chicken. We can't change that part of our identity, so either the other side goes or we do.
With a far weaker form of identity politics, the Republican side can leave behind the culture war much more easily -- worst comes to worst, "Render unto Caesar the things that are Caesar's". (That was Jerry Falwell Jr.'s appeal to evangelicals who may worry about Trump's personal life or faith.) There still has to be a powerful enough economic motivator, but when the economy is doing as awful as it has been for lower and middle-class people, the shift out of identity politics and toward class is all but inevitable.
On the Democrats' side, there's a similar shift but it's softer and halting. On basic economic matters, blacks have done horribly, so they ought to be rallying around Sanders. But he's not peddling that much in the way of feel-good identity politics, and has largely side-stepped the culture war. And their identity as blacks is innate, unlike being an evangelical Christian, so the lure of identity politics is more salient and tempting.
Ditto for women -- if they're young and saddled with student loan debts, they want to vote for Sanders, but then again the appeal of Hillary to their innate identity gives them some pause and some of them will blink. Generally, though, women do not form an organized political bloc because men and women have to help each other out, whatever the political goal is. So even though sex is every bit as innate as race, it's not as natural of a political fault-line (unlike race, which is more obviously tribal), and class-minded women are finding an easier time writing off Hillary than are class-minded blacks, Hispanics, etc.
This also explains why the gays are so all-in for Hillary -- there is no class angle to sodomy. There are any number of "intersectional" topics about blacks unemployment, black imprisonment, black housing, and so on and so forth. Likewise for women having maternity leave, equal pay for equal work, promotion rates, etc. Having one foot in a class topic allows members of an identity group to put aside the culture war for a moment and focus on getting a decent material standard of living.
There is no such thing on the political battlefield as gay employment, gay imprisonment, gay housing, gay income, gay debts, etc. Oh sure, they can try to make stuff up -- "gay discrimination in ads for housemates," AKA "I don't want some creepy fag spying on me in the shower". But everyone recognizes it as bullshit and does not treat it as the Next Big Moral Panic in "intersectional" identity politics. It's simply much more difficult for gays to face any kind of discrimination because they're harder for the average person to spot and to target, compared to blacks, Mexicans, women, etc.
The closest it gets is their anxiety about indulging in so much filthy deviance and having the public foot the bill for the doctors to clean up after their hedonistic mess. But that's minor in the overall scheme of the political economy.
With only born-this-way identity politics on their minds, the gays are rallying 100% around the culture war candidate, Hillary Clinton. They could not be more flabbergasted by the appeal of the class candidate, Bernie Sanders, for the young college crowd. It turns out that all those homo-enablers in the undergraduate student body will cut the culture war loose and vote for the class-oriented candidate when they have more important things to worry about, like crushing college loan debts.
I'll take that as the silver lining of the student loan bubble -- at least it's getting airheaded young people to vote on class rather than affiliation with fudgepackers and AIDS mummies.