More than 30 former federal judges have asked a federal judge in Florida to examine whether the administration’s reported $1.8 billion settlement resolving President Trump’s lawsuit against the IRS may constitute a “fraud on the court,” escalating what had appeared to be a closed dispute into a potentially significant fight over judicial integrity and executive-branch litigation conduct.

The filing is notable not because it decides anything on the merits, but because of who is making the request and what doctrine they are invoking.