A good starting point would be the SCOTUS opinion, or everything on SCOTUSblog, especially the application for injunctive relief filed on Aug. 30. There is a long sequence of petitions and orders which ask the courts either to issue an injunction preventing the law from taking force, or to vacate an administrative stay of proceedings by the lower court regarding petitioner's challenge. The lower court denied the petitions, therefore petitioners turn to SCOTUS to get an injunction against the law.
Then you can turn to the SCOTUS opinion to see what the reasons were, for and against the petition. The majority position is that
an applicant must carry the burden of making a “strong
showing” that it is “likely to succeed on the merits,” that it will be
“irreparably injured absent a stay,” that the balance of the
equities favors it, and that a stay is consistent with the
The majority concludes that
The applicants now before us have raised serious questions regarding
the constitutionality of the Texas law at issue. But their
application also presents complex and novel antecedent procedural
questions on which they have not carried their burden.
Immediately after this the court comments that
federal courts enjoy the power to enjoin individuals tasked with
enforcing laws, not the laws themselves.
it is unclear whether the named defendants in this lawsuit can
or will seek to enforce the Texas law against the
applicants in a manner that might permit our intervention
The law states that
Any person, other than an officer or employee of a state or local
governmental entity in this state, may bring a civil action against
any person who
and the named respondents (government workers of various sorts) all appear to be precluded from filing an action – thus an injunction against the judge is superfluous since he cannot file a lawsuit anyhow. It is also unclear whether SCOTUS
can issue an injunction against state judges asked to decide a
lawsuit under Texas’s law.
When SCOTUS say "it is unclear" in this context, they mean that petitions did not adequately demonstrate that the court can in fact issue such an injunction.
It's not that SCOTUS cannot decide such matters after extensive consideration of the facts / arguments and discussion, it's that the standards for an emergency action require something that the court found lacking in the petition:
we cannot say the applicants have met their burden to prevail in an
injunction or stay application. In reaching this conclusion, we
stress that we do not purport to resolve definitively any
jurisdictional or substantive claim in the applicants’ lawsuit.