In the McDonnell case, it was proven that Jonnie Williams, the CEO of a dietary supplement company, gave [former Virginia governor Bob] McDonnell an engraved Rolex watch, took McDonnell’s wife Maureen on a $20,000 shopping spree at Louis Vuitton and Oscar de le Renta in New York, loaned the couple over $100,000, and much more. In return, McDonnell set up meetings for Williams with Virginia officials that Williams used to push for the state to fund studies on the effectiveness of his supplements, pestered his staff about it, let Williams throw a product launch lunch at the governor’s mansion, and allowed Williams to add himself and associates to the guest list for a reception for state healthcare leaders. Williams himself testified that the gifts he gave the McDonnells were “a business transaction.”
But so what, wrote Chief Justice John Roberts: “Conscientious public officials arrange meetings for constituents, contact other officials on their behalf and include them in events all the time.” If McDonnell’s conviction stood, “officials might wonder whether they could respond to even the most commonplace requests for assistance, and citizens with legitimate concerns might shrink from participating in democratic discourse” – since presumably all citizens buy their governor’s wife a full length white leather coat and pay for him to go see the Final Four.
Or, you know, those public officials could refuse to do favours for donors, and treat them like any other citizen (and behave like elected representatives in any other modern, western democracy: non-corruptly, and with a sense of decency). But then they might not get all that money. So, instead, the Supreme Court has basically legalised the most egregious corruption, and provided you never say "here's $100,000 for your vote", you're in the clear.
And then they wonder why no-one votes. Because doing so simply legitimises the corruption of the few, while enabling them to rule over the many.