Re: The problem is a disenchantment or disillusionment with the powers in authority
The problem is more complicated than "the government is not seen as acting morally or ethically" or "political authority has lost its moral mandate." Those are results more than causes.
"The government" has been oversold as "runner of the country" (or sometimes economy) which, in the case of any country with a legal market economy, which is to say one much to the "right" of North Korea, is ludicrously false. As a result, when things go wrong, as inevitably will happen, the government is constrained to accept a portion of the responsibility and blame, maybe a large one. Because it comes to be seen as ineffectual, possibly a participant in what went wrong, the government loses authority, the right to issue commands within a defined scope and have them obeyed (relatively) unquestioningly.
"The government" also is portrayed, with enthusiastic support of both candidates for elected offices and civil service officials in some of the agencies the elected officials create; as the righter of wrongs, deliverer of benefits and favors, and transferrer of resources from those with substantial resources and few votes to those with many votes and few resources. The voters, like the officials, proclaim these actions to be based on rights to avoid condemnation for being little better than thieves and racketeers and to persuade themselves of their moral rectitude. Some, maybe an increasing number, see this differently and come to doubt its righteousness and question its authority.
Finally, as enforcer of the rules that deal, at bottom, with right and wrong, "the government" is in a scarcely tenable position in a country with as varied a population as the US (or, for that matter, the UK, Netherlands, Belgium, France or Germany) where the basis of right and wrong, and more particularly its detailed content, are disputed loudly, often, and sometimes violently Putting that together with the absurd notion that these questions can be decided for all by a majority vote has got us to a rather bad state of factionalism from which I do not see any likely deliverance.
But have an upvote anyway.