On its face, you can see a rationale for it. Personally, I would agree that Bloomberg would be a better President than Trump or Sanders. He wouldn’t have to spend any time raising money, which eliminates a lot of organizational problems. Finally, he undoubtedly thinks he can win 25 percent or so of both the Democratic and GOP votes–perhaps that would be enough to win.
Or not. When you break it down on a state-by-state basis, it doesn’t work. As an avatar of “New York values,” he would have absolutely no chance of beating Trump in any of the red states; I doubt he would even bother to campaign in, say, Alabama or Mississippi. He would split the Democratic vote in the blue states and potentially throw them to Trump, as well.
The bottom line is that his candidacy would result in an overwhelming victory for Trump. Let’s hope we never find out.