The 0% interest rate cut was supposed to be the last bullet and the Fed has very likely used it up too early. I suspect there was pressure from Trump to do something right this instant, because I don't see the Fed doing this out of their own accord. Possibly election related, we'll never know.
What can they do now? Negative interest rates? Everybody will withdraw their accounts at the same time. Combining this with the zero reserve requirements that was put into force for most banks, this is a recipe for a disaster unlike any we've seen before.