The money already spent on their behalf is not hypothetical, and neither is the implication that the Kochs will provide more if the ruling is in their favor. There will be no evidence for it after the fact, that's the big benefit they receive from ruling that dark money should be anonymous.
The reason why I'm going hard on you for this is because you've made a serious allegation that doesn't fulfil the requirements of the term you used.
When I questioned you about it and asked what two present interests exist that would interfere with the judgement, since you need two conflicting interests to have a damned conflict of interest, you were unable to name them and kept back-tracking to a past donation which is irrelevant and in no way indicative of future gain or loss, financial or otherwise. When I asked you about whether or not one side of the suit was a former client, you again were unable to answer and flipped it the other way around for some reason, which doesn't work. The justices never represented that side of the case in a court of law (that we know of) and as such it cannot be considered a former client. When I questioned you about supposed donations to the Supreme Court, which to my knowledge aren't a thing, you stated that they don't receive monetary contributions, but now they totally will, based on nothing.
In other words, you've concocted a conspiracy theory and expect it to be accepted as gospel. You have no evidence of any existing interest, you just *think* there is one on the basis of a donation. In your mind that creates an obligation, which it does not - the stakes for the justices are zero. They have no interest in terms of their position, which is a lifetime appointment that the side of the case cannot affect, and no interest financially, since they don't receive donations either way, nor would they have any reason to receive them.
Your only actual argument is the idea that they might be bribed, which you have no evidence for, and when questioned your line of defense was "hey dude, it only makes sense, don't make it 2+2=5, follow the money my man". Uh, no. This is an Alex Jones-level argument. Either you can describe a present, relevant and opposing interest or you can't - anything beyond that is your own conjecture. If the justices can't gain or lose anything on the basis of their judgement, there is no conflict of interest - they don't have an interest to begin with if nothing is at stake.