No. Private citizens are entitled to privacy and their rights to such should be guarded by both law and responsible security practices at the companies they entrust with their information. Private citizens shouldn’t be shielded from privacy violation by hiding behind the plausible deniability of no DKIM verification. The communications of public officials should be subject to traceability and authentication as having actually come from them, even if they have gone rogue and used non-government-approved communication channels. If corruption is suspected because communications are discovered on the receiving end, say at a company that gets audited or something, it should be simple for investigators to verify the authenticity of those emails. Establishing ownership of the sending email address is another issue, but I imagine that’s possible via regular investigative routes.

This has nothing to do with “blackmailing public officials” and for you to imply that I have such a desire is both uncivil of you to say here and says a lot about your world view. Blackmail is when you use evidence of illegal activity in order to coerce someone to do something against their will. Transparency and audit ability of our public servants is not blackmail.

Yes, there it is a valid objective in ensuring that elected officials' conduct is above board. However, abusing a spam-mitigation system for this purpose, drawing in every private individual with the dragnet, is the wrong way to go about it.

One key flaw in your argument is that you seek a system that works, "even if they have gone rogue and used non-government-approved communication channels", which, it should be plain to see, absolutely does not apply to DKIM.

I perhaps read a bit too much into your statement, "Blackmail related to embarrassing sexual proclivities or anything like that is unfortunate, but kindly asking politicians to be transparent isn’t a realistic answer."

You're advocating a standard that hurts innocent people in favor of the provably guilty.

I have sympathy for the "provably guilty", as I've seen plenty of places and times where that group includes many noble and good individuals.

In this case, it seems calculated to allow someone to get away with lying to the public about meeting with and knowing nothing about deals with an executives of a foreign state-owned company that has been accused of bribing the US government and corruption.