It's cloudy language, but in California, the term limits for governor were added by the same proposition 140 that added term limits to the legislature. Applying the explicit rules for legislators to executive offices would mean that someone could run for governor only if they hadn't served more than four years. So if Newsom had to serve part of Brown's term, he could only run for a second term of his own if he resigned before the fourth anniversary of when he took office.
Sounds right, though it could end up before court for decision.
