California and other states ruled against by the judge will likely challenge the decision by appealing in the United States Court of Appeals for the Fifth Circuit.
https://www.foxnews.com/politics/obamacare-ruled-unconstitutional-by-texas-judge
I wonder if this is similar to when the Obama administration would not defend the Defense of Marriage Act. If the Trump administration signals to the court that it will not defend Obamacare, it might be that the court can let the matter drop. If I recall correctly, at the time, Roberts was reasoning to the effect that the people elect Congress to pass the laws, and that the Court was reluctant to second guess Congress. Now though, if neither Congress nor the Trump Administration will defend Obamacare, maybe Roberts will consider the Obama refusal to defend DOMA as a precedent.
I had noticed the intent of the California AG to appeal but thought of the Supreme Court decision in Hollingsworth v. Perry. This was the gay marriage case arising from Proposition 8. The district court held Prop 8 as unconstitutional and the state refused to appeal. The Supreme court ruled that the proponents of the proposition did not have standing to appeal either to the 9th Circuit or to the Supreme Court which resulted in the district court decision being the final decision.
This case is based on a federal statute where Hollingsworth originated from a state constitutional provision but the issue of standing should be the same. Since Hollingsworth held that only the state had standing to appeal, a case could be made that on a federal case, only the Justice Department would have standing. The various state attorney generals should have no greater standing than the proponents of Proposition 8.