That ruling is in Yechaveh Da’at, part 5, siman 64. I’d be glad if the Rabbi could look at it in his spare time. And also regarding the claim that we are only obligated to obey the laws of the government/kingdom, but not Supreme Court rulings—what does the Rabbi think about that?
If we assume that Jewish law would exempt Torah scholars from taxes even though the law requires them to pay, why would he still be obligated to pay if Jewish law exempts him? Because morality requires it? One could also question how much morality really requires it, since if we accept the assumption that Torah scholars are lofty people, etc., who sustain the world and without whom the world would collapse (I’m exaggerating, of course), then they’re basically already “paying” us enough taxes, so the moral argument also falls apart…

I went over it quickly. His first claim—that the law of the kingdom is law even in the Land of Israel—is unnecessary. The obligation can also stem from communal enactments, which certainly apply in any community. His second claim—that one may not impose a tax on Torah scholars—I didn’t see in his words why that would override the law of the kingdom. Nor have I seen that if they did impose it, it would not take effect. Nor have I seen what the law is regarding a state that does not conduct itself according to Jewish law. The whole thing seems absurd to me. Obviously one must pay taxes according to the law. Besides,
they also receive services in exchange for the tax, and if they do not pay, that is theft (even according to the view that it is forbidden to impose tax on them), and the concept of taxation today is different from what was accepted in their times.
Someone who contributes to the economy also contributes thereby to Israel’s security. Can he also evade taxes because of that?

I didn’t see what he said about the Supreme Court (as I said, I skimmed quickly). On the face of it, that too is completely absurd. It is no less binding than communal enactments, and besides, the law of the kingdom is what gave them their authority.

The part about the Supreme Court actually refers to Tzitz Eliezer, vol. 16, siman 49, section 14.
If I understand the Rabbi correctly, he is saying that even if Jewish law were to forbid imposing a tax on Torah scholars, nevertheless if the state chose to impose one, then the Torah scholar is obligated to pay it. And the only cases where one is not obligated to obey the state are specifically when the state tells you to violate Torah prohibitions. But if the state acts against the Torah, that does not mean we are not obligated to obey the consequences of that action.

I’d be glad if the Rabbi could take a quick look there in Tzitz Eliezer.

I took a look. He argues that if there is an obligation to obey a court (and not a direct order from the king), then you have nullified the prohibition against gentile courts.
That is not relevant to the Supreme Court, because the Supreme Court interprets the law, and that is like a direct order from the king. Moreover, a Supreme Court ruling is not a judicial instruction but law. They do not deal with a specific person, but with interpretation of the law itself. So there it is certainly not relevant.
For my own part, I think that even the prohibition of gentile courts is not present here, or more precisely, there is no obligation to heed him. See the Tur, section 448.

Understood. Thank you very much.

In the words of Yechaveh Da’at [that the law of the kingdom is Torah-level law even with regard to a Jewish king in the Land of Israel, and even an idol worshiper, and the same applies to a government, even a government of lawless people, and therefore it is forbidden to evade customs duties: “However, we must make it known that according to Jewish law it is forbidden to impose a tax on Torah scholars who are engaged in Torah study”]

A. You said that even if there is no permission to impose a tax on Torah scholars, perhaps under the law of the kingdom there is permission, and even if the kingdom has no permission, if it imposed it then the law still binds. [True, Yechaveh Da’at does not deal with this, and perhaps indeed so, but I’ll ask about the suggestions themselves.] The suggestion that under the law of the kingdom there is permission is not clear to me. Against whom, then, did they say that there is no permission to impose a tax on Torah scholars? Surely they were addressing the body that can impose taxes on everyone else—in other words, it has the authority of the law of the kingdom for that—and to that body they said: you do not have permission to impose a tax on Torah scholars. And the suggestion that even something a king is forbidden to do, if he transgressed and did it, still has the force of the law of the kingdom, does not seem so reasonable in itself. There is also proof for this from the words of the Nimukei Yosef cited there, who rules that everything stated in the passage of the king is forbidden to the king, and therefore even Jewish kings do not have “the law of the kingdom is law”; rather, they judge only according to Torah law. It follows that the Nimukei Yosef understood that if something is forbidden on the king’s side, then it also has no force under the law of the kingdom. And the same would apply if it is forbidden to impose a tax on Torah scholars—then it has no force under the law of the kingdom.

B. Regarding a state that does not conduct itself according to Jewish law—did you mean to give it additional power, so that it would have the power to impose taxes on Torah scholars, even though a state that does conduct itself according to Jewish law has no power to impose such taxes and they have no validity?

C. Regarding your point that the concept of taxation today is different from what was accepted in their times. Presumably your intention is that in their times taxes were to enrich the king’s treasury, whereas in our times taxes are to fund public functioning. But clearly in their times too public functioning required funding, such as maintaining the roads and employing police, and that funding also came from taxes—and Torah scholars were exempt even from that tax.
Therefore, regarding what you said that they receive services in exchange for the tax, and if they do not pay it is theft—this too needs discussion. Seemingly, with public services (such as paved roads), certainly a Torah scholar exempt from tax may use them, for otherwise what practical value is the exemption? And the public is obligated to include them. As for private services such as allowances and grants to an individual, which are apparently a new development of recent generations, the question remains whether a Torah scholar exempt from tax may maneuver and take them. But this distinction between private and public services is very vague; and if the matter is based on that, then more simply one could say that there is no distinction between the two, and whatever the individual receives, he receives as part of the public.

A. A community also imposes taxes. And in many cases, even when the king imposes taxes, the community distributes them among its members. I do not think the comparison to a Jewish king is appropriate. He has a prohibition because he is Jewish and subject to Jewish law. That does not mean he lacks authority. For example, is a gentile king forbidden to have many wives and horses? Certainly he is permitted. A Jewish king is forbidden, but that does not mean this is not within his authority.
B. Same answer. They all have the power to impose taxes, but it is forbidden.
C. I disagree. A Torah scholar cannot use the road if he does not pay taxes, if the public forbids him to do so. The fact that they do not impose taxes on him does not nullify the prohibition of theft. The same applies regarding the public’s obligation. Even if the public has an obligation to include him, it is the public that decides this. I have an obligation to give charity, but that does not mean a poor person is allowed to take it from me.

https://e.walla.co.il/item/3519222