If elected, Democrats would have good cause to distrust his instincts. Bloomberg is close to Wall Street, which he ludicrously absolved of blame for the financial crisis, and is generally over-trusting of the rich. Only after announcing his candidacy did he offer belated and a patently insincere apology for the stop-and-frisk policy that justifiably angered so many of his nonwhite constituents.
But some of these concerns would be resolved simply by dint of Bloomberg running as a Democrat. This is an era of party government, and while the president’s talents and beliefs matter, the personal idiosyncrasies of any one officeholder are usually swallowed up by his political coalition. This is why Donald Trump defied the distrust of his fellow conservatives and has governed in an ideologically — if not personally — conventional style. Bloomberg’s platform has largely converged with the Democratic mainstream.
Whether his commitments to party constituencies are sincere hardly matters, because his incentive to hold together his coalition is the binding force. Trump used to identify as a proudly pro-choice Democrat, and then as an independent. No reversal was more laughably insincere than Trump’s conversion to the pro-life cause, yet he has held to that stance because it is in his interest as a Republican to do so.