Hoo boy. Where to start with this? Let’s take a look at the populist angle first, especially in light of the Democrats’ all-in approach to class warfare. In times past, kingmakers had the good sense to work behind the scenes. They also had the good sense not to flaunt their wealth too much to the hoi polloi, who might get turned off by the 0.0001% dictating electoral outcomes.

This is why people in Bloomberg’s position use PACs and other groups to at least pretend that they’re part of a consensus. To put the shoe on the other foot, Democrats have often accused the Koch brothers of buying offices for Republican candidates, but they usually limit their involvement to policy issues rather than candidates. Imagine, if you will, what NBC and other media outlets would have had to say had the Kochs set up a parallel campaign structure for Mitt Romney in 2012 and spent $100 million to get him over the line against Barack Obama. “Buying a presidency!” would have been the least of the complaints.

Of course, Trump’s a multi-billionaire himself, and one who improbably has managed to ride a populist wave to office. Needless to say, that’s not Michael Bloomberg’s forte, even if his wall-to-wall advertising is posing him as such. Furthermore, Trump promoted himself and self-funded part of his campaign, not someone else’s. (And wouldn’t have, either; if it didn’t benefit himself, Trump wouldn’t have gotten involved.) Bloomberg’s spending on his own behalf is rather mundane in a campaign-finance regulatory environment that incentivizes recruitment of self-funders, but maintaining a campaign explicitly for someone else’s benefit? That’s a new innovation, and a somewhat disturbing one.

It also would put the Democratic nominee in a very odd position, especially in regard to the party’s progressive base. At the moment, the big fight between the frontrunners is just how much each of them has sold out at one time or another to deep-pocket donors looking to exploit them. In that context, how gladly will the eventual nominee be to paint Mike Bloomberg as “the most important person” to the Democrats and him/herself? Especially because of his vast wealth and power?

And then there’s the issue of media coverage. Bloomberg owns a large media corporation that covers politics generally and the president election specifically. Bloomberg the Owner has already seriously damaged the credibility of Bloomberg the Media Outlet by ordering his staff to stop doing investigative reporting on Democratic candidates but to continue them on Trump. Even other media outlets consider than an untenable position. Now Bloomberg the Owner plans to sign up not just to run for president, but failing that, to take down the incumbent. Whatever credibility Bloomberg News has left will get utterly destroyed in that process, not just in political coverage but in anything that impacts politics — such as its coverage of the economy, Bloomberg News’ core beat.

Let’s put this another way, too. If Rupert Murdoch launched a $100 million campaign to re-elect Donald Trump, complete with media blitzes and ground organization, every other media outlet in the world would be shrieking about “state owned media” and corrupted capitalism. The Murdochs would be demonized and vilified and their reporters completely discredited. No one is naive enough to think that Bloomberg and his media empire would suffer the exact same fate, but it’s going to prove corrosive nonetheless. Everything Bloomberg News would be seen through that prism, and rightfully so.

At the very least, this will put a severe damper on the chronic chest-beating over Citizens United. That alone might make it worth the nonsense.