The general rule is that a state bar an attorney is admitted to may sanction, including disbarment, the attorney for conduct that reflects poorly on the attorney's fitness, regardless of where the conduct takes place.
Warren's supporters seem to have backed off the "its Federal Court so its OK" defense. There seems to be a lot of confusion about that issue. I am licensed in state courts in Texas, and in the local United States District Court, and the United States Court of Appeals for the Fifth Circuit. The 5th Circuit is head quartered in New Orleans, but I have not practiced law without a license, in Louisiana, by filing motions, or briefs, with the 5th Circuit. Even if I appeared for oral arguments before the 5th Circuit, in New Orleans, I would not be practicing law without a license in Louisiana, because I would be in front of a Federal tribunal. That is the "Federal Court" exception Warren's supporters were making so much noise about a few days ago.
But that does not mean that if Tulane School of Law went nuts and made me a professor, that I could move to Louisiana, stay there for decades, practice law, and never get licensed in Louisiana. It is possible that if all of my law practice was representing illiterate first offenders, whose only legal issue was an appeal of a criminal conviction, before Federal Circuit Courts, or the Supreme Court, that I could argue that every single action I took, and piece of advice I gave, was covered by the "Federal Courts" exception, and that I was not practicing law in Louisiana without a license.
But Warren's clients were multi-billion dollar corporations, who had numerous, intertwined, legal issues. These corporations have in house legal departments, and outside law firms, apart from Warren (look at the signature pages that have been posted -- each one I saw had additional law firms). How could Warren advise them on the case she was hired on, without also advising them on other pending cases, in Federal Courts that she is not admitted to, or in state, or foreign courts, or cases yet to filed? Since Warren is a bankruptcy "expert" how could she advise her clients on the case she was hired on, without also advising them about how to best position themselves if the case was lost on appeal? All of that would, in my opinion, constitute the practice of law, and would not fall under the "Federal Court" exception.
Well, I can think of one way Warren could have not been practicing law without a license in Massachusetts. What if she really didn't do anything substantive? What if her corporate clients didn't want her legal advice and counsel, but just wanted the cachet of "Harvard Law School" on the signature page of their brief, and the political cover that having a leading lefty professor endorse their position would give the court hearing the appeal, so they just paid her to sign off on briefs that someone else had written? That might get Warren off the hook legally, but it would be politically disastrous.
-— What if her corporate clients didn’t want her legal advice and counsel, but just wanted the cachet of “Harvard Law School” on the signature page of their brief, ——
It’s that, influence buying, or a quid pro quo.
I’d be shocked if she did any work.
After all, she’s busy teaching one course a year, for only 300 large.
She’s a regular Mother Theresa.