Given all the recent focus on health policy, you might think that the medical-industrial complex would be heavily involved in the Democratic primary race, going all-out to block Elizabeth Warren. And a coalition of drug companies, insurers and hospitals is indeed running ads attacking “Medicare for all.”

But the health industry’s political role has been relatively muted so far. Partly this may reflect realism: Even if Warren becomes president, the chances of getting Medicare for all through Congress are small. It may also reflect the surprising openness of doctors to reform. While the American Medical Association still officially opposes single-payer, at a recent meeting, 47 percent of the delegates voted to drop that opposition.

No, the really intense backlash against Warren and progressive Democrats in general is coming from Wall Street. And while that opposition partly reflects self-interest, Wall Street’s Warren hatred has a level of virulence, sometimes crossing into hysteria, that goes beyond normal political calculation.

What’s behind that virulence?

First, let’s talk about the rational reasons Wall Street is worried about Warren. She is, of course, calling for major tax increases on the very wealthy, those with wealth exceeding $50 million, and the financial industry is strongly represented in that elite club. And since raising taxes on the wealthy is highly popular, it’s an idea a progressive president might actually be able to turn into real policy.