The next big thing would be for the Fed to start buying stocks directly, probably through ETFs, which is something it currently can't do. At the moment it can only buy mortgage backed securities and bonds.
As for why they're doing this, well, monetary stimulus is really all the Fed can do, ineffective as it is, and in the vacuum of fiscal intervention from Washington I guess they feel that someone has to do something. By cutting all the way to zero they also put the ball in the government's/congress's court so the focus is on their inaction, where it should be.
There's a ZeroHedge article that says this would require Congress. Is that true?
FWIW, there is precedent for this. The Bank of Japan owns something like 70% of all stocks in Japan via ETFs.
Trump made a HUGE deal of being “so surprised” that the announcement by the fed was made just a few minutes into his live press conference. He kept saying over and over that he had no idea this was going to be announced at such an opportune time.
Of course it’s political.
For the downvoters: feel free. You're just ignoring the new reality. I'm not a supporter of this administration. But I'm a realist.