Bernie is a natural born revolutionary, and like other profit types pointing the way, history teaches that such revolutionaries make for poor leaders.
It’s all very simple. If the purists on the left get there way and Bernie is nominated, Trump wins.
If on the other hand the pragmatists of the Democratic Party prevail and Bloomberg is nominated, Mike will pick up many independents and a heck of a lot of stealth Republicans, and Trump will easily be defeated. Even if you think its a choice between two evils, the lesser evil, Bloomberg, is always the wise choice, which in this case your vey life may depend on it.