One under-rated determinant of political debate lies in the fact that we become accustomed to some things but not others.

I'm prompted to say this by reactions on Twitter to my questions about Mark "Herr Juncker in the bunker" Francois: how did this idiot achieve prominence? Why does the BBC think him an acceptable guest on what it considers a serious show? Why have our selection mechanisms & standards gone so badly awry?

Some replied that the BBC is chasing click bait, or that it is human nature for people to cheer on those on their own side, regardless of their competence.

What such replies miss, however, is that these phenomena are more prominent now than they used to be. I might be guilty of selective memory or golden age mythologizing, but I don't recall John Tusa interviewing as many performing baboons on Newsnight in the 80s as Emily Maitlis does now. Of course, many MPs in the past were buffoons or wrong 'uns, but they rarely achieved great prominence and if they did get into government they were usually found out, and if sacked in disgrace they did not often return swiftly to government as Patel and Williamson have. The prominence of low-grade MPs is relatively new. We should not take it for granted, but ask how it happened.

Equally, the BBC's non-existent editorial standards - which allow it to uncritically report Trump's obvious nonsense about a UK-US trade deal could lead to a "three to four, five times" increase in trade - should not be taken as normal.

These, however, are not the only examples of what I mean, or even the best ones. There are others:

- We think it natural that young people should be left-wing and so support Corbyn. This is not so. In the 80s, the Tories won more votes from under-35s than Labour did. The much-caricatured yuppies were Tories, not hard leftists (except me).

- We've become accustomed to think the main dividing line in politics is between Leavers and Remainers, leading to talk of post-party politics. But in fact, the words "Leaver" and "Brexiter" meant nothing just four years ago, when only a handful of cranks were obsessed with the EU: less than 10% of voters thought it the most important issue before 2016. And when the Tories let themselves get obsessed with Europe in the 90s, they were obliterated in general elections (Blairites might have a theory as to why).

- Many people have resigned themselves to the fact that austerity cost us more than 10% of GDP and many lives. The Lib Dems can therefore plausibly ask us to move on from austerity and fight Brexit instead. The potential cost of Brexit is seen as much nastier than the cost of austerity, even though it is probably smaller.

- People adapt to inequality: as it rises, so too do our ideas of what level of inequality is acceptable. In this way, we resign ourselves to it.

What's going on in these cases are specific instances of a widespread phenomenon: adaptation. We get used to most hardships and even to the most abject poverty. Often our mental health and even our survival require us to do so. But this comes at a price - that we accept the unacceptable. As the old saying goes, it is easier to ask forgiveness than permission (which seems to be the nearest Lib Dems have to a political philosophy).

This generates a status quo bias - a tolerance of big existing evils but resistance to even small threats. Those who expect us to get over austerity want us to think that the possibility that Corbyn's tax rises will slightly shrink GDP is intolerable.

Oppressors everywhere have exploited this. Generations of us sang that "He made them high and lowly, and ordered their estate." Misogynists pretend that gender roles are natural and not social constructs. Right-libertarians want us to think that capitalism is natural whereas in fact it is the product of coercion; it came into the world "dripping from head to toe, from every pore, with blood and dirt." Racists have always looked for some "natural" inferiority in black people. And escapees from North Korea are often surprised by the wealth of the west because they've been indoctrinated to think abject poverty is widespread and normal.

We must of course resist all this. Socio-political structures and beliefs are not natural and inevitable but are instead products of human action if not design. We should therefore resist what Trotsky called kowtowing before accomplished fact. Instead, we must ask: how do some issues come to dominate bourgeois Westminster politics whilst others are off the agenda? How are political identities shaped so that cultural ones (Leave/Remain) efface class? Why has capitalism changed in the last 30 years to alienate young people? Why are selection mechanisms in politics and the media now less effective at filtering out idiots and charlatans? How did the BBC come to be infected with crass consumer culture to the detriment of public service broadcasting? And so on.

If we think of politics merely as our tribe against theirs, we ignore such questions. And guess whose interests this serves?