WASHINGTON—Shortly before his death in February 2016, Supreme Court Justice Antonin Scalia spoke favorably of Donald Trump’s presidential run.

“Justice Scalia thought it was most refreshing to have a candidate who was pretty much unfiltered and utterly frank,” said the late jurist’s literary collaborator, Bryan Garner, a legal dictionary editor who spent two weeks in 2016 traveling with Justice Scalia through several Asian countries.

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