WASHINGTON—The Senate next week , on his legal philosophy. A look at his writings reveals what senators will likely find: a consistent push to restrain the regulatory state.

That was clear in a Senate questionnaire item asking him to list his most significant opinions as a federal judge. Judge Kavanaugh, who sits on the U.S. Court of Appeals for the District of Columbia Circuit, chose a 2008 dissent in which he suggested the high court erred in its unanimous 1935 decision upholding the constitutionality of independent agencies...