The judge in Donald Trump's hush money trial declined Monday to broaden the scope of testimony that the defense can elicit from a potential expert witness, Bradley A. Smith, a former Bill Clinton-appointed Republican Federal Election Commission member.
Judge Juan M. Merchan echoed his pretrial ruling that, if called, Smith can give general background on the FEC - its purpose, background and the laws it enforces - and the definitions of such terms as "campaign contribution."
Merchan rejected the defense's renewed efforts to have Smith define three terms in federal election law, saying it would breach rules preventing expert witnesses from interpreting the law. Nor can Smith opine on whether the former president's alleged actions violate those laws, Merchan said.
If Smith were to testify about those issues, Merchan said, the prosecution would then be permitted to call an expert of its own. That would result in a "battle of the experts," the judge said, "which would only serve to confuse and not assist the jury."
Smith is a law professor, and that there often are guardrails around expert testimony on legal matters, on the basis that it's up to a judge - not an expert hired by one side or the other - to instruct jurors on applicable laws in a case.