Supreme Court nominee Brett Kavanaugh says he has not taken a position on the constitutionality of investigating a sitting president. Yet his past writings cast doubt on the idea.

Asked by Sen. Amy Klobuchar Wednesday whether he believes such investigations are only acceptable in impeachment proceedings, Kavanaugh replied: “I did not take a position on the constitutionality. Period.”

WATCH LIVE: Day 2 of Brett Kavanaugh Supreme Court confirmation hearing

In a footnote to a 2009 law review article, Kavanaugh wrote that “a serious constitutional question exists regarding whether a President can be criminally indicted and tried while in office.”

A decade earlier, Kavanaugh wrote that the Constitution seems to dictate that “congressional investigation must take place in lieu of criminal investigation when the President is the subject of investigation, and that criminal prosecution can occur only after the President has left office.”

Kavanaugh also declined to answer questions about the extent of the president’s pardon power.

"President Trump claims he has an absolute right to pardon himself. Does he?" @SenatorLeahy asks.

"The question self-pardons is something I've never analyzed," Brett Kavanaugh says in part. It's "a hypothetical question that I can't begin to answer in this context…" pic.twitter.com/n0WCDr9bP3

— PBS NewsHour (@NewsHour) September 5, 2018

Democratic Sen. Patrick Leahy of Vermont asked Kavanaugh: “President Trump claims he has an absolute right to pardon himself. Does he?”

Kavanaugh responded that the question was a hypothetical one he “can’t begin to answer in this context as a sitting judge and as a nominee to the Supreme Court.”

Leahy followed by asking whether the president has the ability to pardon someone in exchange for a promise not to testify against him. Kavanaugh declined to answer.

Leahy concluded by saying: “I hope for the sake of the country that remains a hypothetical question.”

President Donald Trump has declined to rule out pardons for people convicted in special counsel Robert Mueller’s Russia investigation.

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