@Legio_Italica
The long term statistical trends which played a significant role in Trump's candidacy (both in the GOP primaries and the general election) have already been established: there had been leftward lurch among Democratic voters; there had been a liberalization - particularly on the left - of attitudes toward immigration; there had been a dramatic decline of conservative voices within academia; the steady decline of both Christianity and the white majority had continued; In 2013, race-relations (which had been strong during Obama's 1st. term) began collapsing.
The Pennsylvania study I provided goes into detail on how some of these trends affect perceived status threat:
From another,
similar study:
From this data/analysis it is fairly straightforward to extrapolate, even beyond racial/demographic issues, that the more openly progressive Democratic voters became, the further conservatives lurched to the right to compensate for it (a conclusion which is borne out by the
data on political polarization). This is an essential reason why, even though the established Democratic candidates never openly expressed extremist positions, their failure to properly denounce the loud activism of left-wing radicals in the so-called "
culture war" (which outlets like Fox News made sure to report on) worked in Trump's favour.
On the point about specific instances of leftist radicalism, I have already cited the European Union's handling of the migrant crisis as an example. The fact that the Democratic Party/Obama administration wasn't responsible for decisions made in Brussels is irrelevant: regardless of where the extremism originated, as a matter of foreign and domestic policy, the migrant crisis (and the spate of terror attacks associated with it) had a material effect on the presidential campaign.
We know, for instance, that it inspired Trump's flagship proposal to "shutdown" on all Muslims migration to the US - an idea which was not only
supported by most Europeans at the time but which also resonated well with American conservatives. This was precisely because, as a candid, radical response to the extremities of hubristic progressive policy making, it allayed status fears among the Republican base - a finding which is absolutely consistent with what we would expect, given the long term statistical trends noted above.
In terms of identifying exclusively domestic cases of radicalism, we could go through a near endless litany of examples ranging from the trivial (obnoxious anti-white content published by
Buzzfeed/
Salon/
MTV) to the extreme (
the mass murder of police officers by a black nationalist), but because the culture war is such a broad subject, and because there are already so many threads dedicated to it in this forum, it would probably be more efficient for you to
read around the subject on your own.
Alternatively, you could just watch South Park.