There was a discussion on this issue on the local talk radio show involving a couple of death penalty defense attorneys who were against this move. They said the significance of Newsome ordering the tear down of the execution room cannot be understated. By doing that, even if a Court were to rightfully rule that he overstepped his powers in doing this the entire process is up in the air now because the methodology that was in place had been tested in Court. Even if you exactly re-assemble the mechanisms now it is subject to challenge in Court again which would mean years of appeals.
A retired judge I work with is actually the guy who prosecuted the last person California executed and he was present at the execution. He said the entire process is so fucked up in California that they may as well just do away with the death penalty entirely because it means nothing at this point. He said the major blow on this is many times they get people who murdered someone to plead guilty and tell them the location of the victim's body so the families have closure by offering to take the death penalty off the table. That option has now been taken away.
As for Newsome saying that the death penalty is racist the defense attorney on that show said it was a flat out lie. No person in California gets the death penalty because they can't afford top notch defense attorneys. All death penalty cases are defended at the expense of the State of California and they have every means available to them for forensic testing and expert testimony.
The death penalty is very rarely given in California. We have over 700 people on death row but their crimes date back as far as 1976. Just think about how many murders occur in California each year. There were over 1,800 murders in California in 2017 alone. Even at only 1,000 a year you are talking about 42,000 murders in California between 2018 and 1976. Out of those 42,000 (which is a very conservative estimate) only 737 murderers ended up on death row. Just 15 of the 135 California death row inmates who have died since 1978 were executed. In fact, execution is only the third most common cause of death on California's death row following natural causes and suicide.