Oh this should be a fun political question. The Times reports on the lawsuit filed by Rangel, asserting:

The lawsuit, filed on Monday in Federal District Court here, claims that the House ethics committee broke its own rules during its investigation of Mr. Rangel, including the inappropriate sharing of confidential evidence by investigators with Republicans on the committee. He also claims that he was denied the right to cross-examine witnesses during his hearing, and that some of the investigators had made racist statements.

He brought suit under the “Rules of its Proceedings” clause, coupled with due process violations. He also asserts that the “speech or debate” clause does not apply because the defendants “intentionally and willfully [were] in violation of what was required to fall within the privilege.”

I can’t imagine the courts want to get involved with this–as the complaint notes, there have been no court cases to interpret the “rules of proceedings” clause.