'I'm now wondering whether they had anything to say, whether they had any argument against him that was either persuasive or effective. '
Spinflight, I don't think they had anything that could win against "take our country back and make it great again". There is no answer that the status quo can offer against that which is why racist was all they could shout, exactly what they did to Farage and UKIP. It worked in the UK because it was a different electoral system and UKIP didn't have the money or the sheer guts that Trump had to go direct to people on social media and huge rallies, but if Banks throws money at it and with Bannon and Trump offering support, absolutely anything could happen.
UKIP didn't have some polished policies, but as we have seen with Trump, policy detail doesn't matter, all the people care about is to trust that things will really be changed. they trust Trump even though they don't really know what he will do.
'do the media and their followers actually believe that name calling and silly innuendo is the debate? '
That is all they have got. It's propaganda and they used it here against Farage and it worked because they outbullied him, but they couldn't outbully Trump because he is bully-in-chief with the hide of a rhino and an insult and a quip to fire back with. Trump was prepared to go where Farage didn't dare, to insult beyond the bounds of what was considered polite and that is why he smashed the Establishment's glass ceiling that kept populists down
'In other words is there actually a section of the population who see political correctness as an end in itself? Politics therefore being a simple game of the most politically correct being the correct candidate, and the less virtuous being almost literally the devil? '
Political correctness is brainwashing, spellbinding, but Trump blew it wide apart and the spell has lost its power.
'I do now wonder whether identity politics has so entrained its adherents that they are no longer able to discern the subtleties of politics'
I think that is its purpose, the Democrats use that to control minds, but Trump drove a coach and horses through it and "broke the chains".
The lyrics in "The Trump Train" shows how Trump broke the chains
Scott Adams, Dilbert creator, predicted Trump would win from the beginning because of his hypnotist magician quality to break the spells, cut the Gordian knot and instinctively reach the people at a deeper level than just words.
'The interesting thing here for me is that policies don't matter,'
That is what Arron Bnks has been saying. "Facts don't matter, it is emtion that counts" and trust is the top among those, can-do, get the job done, sort things out and trust, and that is Trump.
'The absurdity of course is that labelling a group for vilification only works if it is a small group'
Yes, Hillary called the people "Deplorables" and millions thought she meant them. We all know the elites are not on our side, but when they openly show their disdain, then they are bound to lose. Trump said they are "stupid" and "don't care about you" and everyone knew it was true.