Unable to stop the spread completely, on March 19 Newsom became the first governor to issue a shelter-in-place mandate, meaning people shouldn’t leave their homes except for essential needs like groceries and prescriptions. By reducing contact, UC Berkeley epidemiology professor Lee Riley says it’s ”the best strategy” to slow the spread of coronavirus so as not to overwhelm the health care system. 

Right before the state went on lockdown, Newsom wrote a letter to President Donald Trump warning that 56% of Californians, or 25.5 million, might be infected by coronavirus over an eight-week period without preventative action.