And then to have the prestigious Wall Street Journal donate space for him to take his denial to the public...
I find that stranger than the actual gifts. It's distasteful that the Supreme Court members have been financially involved with political allies, but in the end those were allies. I don't believe these are bribes. They're always voting in accordance with their principles. It just so happens that those principles suit their benefactors very well, and they express their pleasure in extravagant ways, but I don't think they'd change their decisions in the slightest if it were stopped.
It has the appearance of impropriety, and they really should be avoiding that appearance. But that has mostly meant keeping out of the limelight. They obviously have political leanings and they express their views, but compared to their office they usually keep a fairly low profile. They like to think of themselves as "calling the balls and strikes", and have lifetime appointments so that they don't have to play politics.
So going to a major newspaper -- one whose opinion page is explicitly partisan -- is even weirder than the gifts. It's dispensing with even the fig leaf of "I'm not being bribed; I just happen to have a lot of generous partisan friends". The usual way to solve this would be to avoid reporters, let the journalists ferret out the facts as best they can, and then let it all die down because there's no actual way to hold any justices to account. (Impeachment exists but is effectively impossible.)
Taking it public like this feels inept. It's the kind of treatment politicians get, and the whole point of their power is that they're pretending not to be politicians. Of course that pretense has been shredded for decades, and it is long past time we reconsidered how it works. And in the meantime, it bodes very, very badly for one political party to more from implicitly to explicitly controlling the one non-overridable part of the government.