It's quite rational.
If she is elected President, it will obviously be a huge home run.
If not, he will have a grateful partisan in the Senate, who will move heaven and earth in the Democratic-majority US Congress to help Morgan Stanley with its legislative agenda.
His number one concern is that Congress - which sets tax policy and regulates financing structures - is on his side.
With a Democrat Congress it cannot hurt him to support the Democrat nominee with the most Congressional support.
I have a securityaccount with Morgan Stanley and seriously reconsidering.
It’s principled business leaders like Mack that make our country great.