Democratic Party contributions = indulgences?

Punitive consequences rings true and isn't one of their stated goals. It certainly follows from the rich-as-exploiters meme, though. Exploiters deserve to be punished. And if you happen to be born to the exploiter class, you have a great deal of original sin to atone for.

They are really seeking redistribuition of wealth or income, or punitive consequences for making or having more than others.

Please note, that I don't buy this narrative, or the related “random luck theory of all consequences.”  I've been among those stressing that “fairness” is being misused here to “justify” progressive taxation in particular as well as the ability-to-pay principle in general.

“I'm with them to a point in supporting progressive taxation. There's a practical reason: I'm going to have to pay for either schools or jails, and I'd feel better if it were the former.  And I think the golden rule is a pretty good basis for policy; progressive taxation is easy to justify on that basis.”

Well, I agree with some of the logic inherent in it, the utilitiarian concept underlying ability-to-pay (how can, let alone should, taxes be paid?) and true fairness or decency in some progressive taxation, notably the concept of an exemption of a minimum income, in the case of the income tax (the most common and even typical tax thought of), as well as considering different values for different marginal incomes.  But an honest admission of what is being sought, and honest explanations why, are long overdue, and there is no reason to engage in “social engineering” and intentional redistribution based on envy and resentment, and other dark motives, which aim for destructive tax and social policy.  And certainly there's no excuse for weasel words that try to dress up sweetly what it is that people (really) are seeking.

(The same is true for public versus private sector presence in society.  Public schools, for example — there is a lot of political baggage, especially since the 1960s, harming public schools and associated parties like teachers' unions.  But do we really want to abolish public schools?  Do we want in reality few but the wealthy and well-connected's children to expect to receive an education?)

IMHO “fairness” is so malleable it's useless as basis for policy, and I think most liberals simply haven't noticed. But I'm with them to a point in supporting progressive taxation. There's a practical reason: I'm going to have to pay for either schools or jails, and I'd feel better if it were the former. And I think the golden rule is a pretty good basis for policy; progressive taxation is easy to justify on that basis.

Well, in some cases I'd have to back off and say they'd just prefer to use one word rather than another, because “fair” or “fairness” captures good feelings (the euphemistic approach), or that they confuse what they want with being “fair” or with “fairness.”  But in other cases, I say they know the distinction between these words and what they actually seek or want (progressive taxation) and they prefer substituting their choice of words because it makes their position and them appear better (to them and to the ignorant, anyway).

Ability to pay as a basis for taxation (and for progressivity) is (superficially, at least) practical.  But “fair”?

In the case of liberals defending progressive taxation as “fair,” you haven't done that. Their use of the word fits pretty clearly within common definitions (“free from bias, dishonesty, or injustice” per dictionary.com). They do perceive societal bias making it easier for the rich to get richer and the poor to stay poor.

To back your charges of dishonesty, you need to show they're deliberately misrepresenting something. You haven't done that either. While I have some skepticism about how much societal bias holds people back, I have no doubt that liberals believe it matters a lot. If you're suggesting they really don't but are merely pretending to for nefarious leftist motives, what might those be?

That would be the the condition and extent (matter of degree) of being fair.

So what's the “honest” definition of “fair”?  That's where the real dishonestly lies.  “Fair” is being misused in place of “desireable” or “desired.”

Sorry, Dr.  I thought you might have missed that point.  In this case, definition is confused with use by the users.  For what you write is how the typical users of the word for tax policy use it (heh):

“I feel it's fair to rob from the rich and give to the poor”

Whether the word has a precise definition is critical. If fairness is a matter of opinion and I feel it's fair to rob from the rich and give to the poor, I'm not misusing the term at all. You may disagree that it's fair, but you haven't substantiated your charge of misuse, much less of dishonesty.

“How progressive should a tax code be to qualify as 'fair'?”

Many say that progressive _is_ fair, (that there are degrees, not merely a threshold, of “fairness”), so the more (progressive), the better (the more “fair” a tax is).

There is a long history of misusing “fairness” and attempting to make it synonymous, with progressive taxation.  (Related to it frequently, incidentally, is a leftist objection to misuse by conservatives in light of tax policy and related issues of the word “successful.”  That the latter word is used pliably doesn't justify more-blatantly-wrong misuse of “fairness,” to try to make people feel good about tax progressivity or merely to dishonestly give progressivity a nicer-appearing veneer.)

The word has no such precise meaning. What's fair depends heavily on your point of view.

Which makes it a questionable principle for policy decisions. How progressive should a tax code be to qualify as “fair”? Does it become “unfair” beyond that point? How do we know what that point is?

I want the word's meaning to be respected, and the word used correctly and honestly.  Leftists do not.  They like using the word “fairness” when referring to progressive taxation, as both a euphemism and as a bogus rationale.  The utilitarian argument (and what accompanies it, such as the progressive devaluation of marginal income, for example) is the sound argument, morally risky as it obviously is.  But for numerous reasons (to grapple with the moral questions or even guilt, to cloud the issue, to feel good about it), the world “fairness” is associated constantly with progressive taxation of income (and wealth), such as in numerous left-side texts on tax policy.

* * *

“There, Social Security-like benefits are paid out of general revenues which are generated by progressive income taxes.”

Actually, the more childish leftists and related people (including Conyers and Medicare for All) can insist on this approach to all federal entitlements here in the USA — making their funding “mandatory” out of general revenues, with the intention to raise these revenues out of progressive income and wealth taxes, and related class-warfare instruments such as the Tobin tax on stock and bond (securities) transactions.  The most dishonest or wacky such people can even claim that deciding to do this instantly “saves” federal entitlements.  (Actually increasing taxes or levying any new taxes is typically left to others, in the future, i.e., the most crucial and controversial details and elements are deliberately neglected or omitted.)

* * *

I'm not surprised you'd be creative as well as tangential with Willie Sutton and Banks 2010, but it's merely a diversion and I won't say any more here about it.

With regards to Willie Sutton, who said he robbed banks because
that's where the money is. If you look at what banks have done with
credit cards in recent years and the way they have feed at the
national trough, it would also be fairer to say that bankers of late
are more like Willie himself rather than victims of the man…

This, separated from everything else, is morally risky, but can stand on its own as a utilitarian gauge of tax policy measures.  (Just don't join other lefties in lying, and misusing the word “fairness” to refer to it or other related approaches to progressive taxation.  At its heart, you are immoral or amoral, and strictly utilitarian.  Possibly “practical,” too; there is a logical and practical basis for the income tax exemption.)

Note that it's utilitarian, and simply rationalizes Willie Sutton's approach to revenue appropriation.