Joe Arpaio liked to call himself “America’s toughest sheriff.”

During his six terms as sheriff, he led his team of deputies in Maricopa County, which includes Phoenix, on a crusade against illegal immigration, turning himself into a nationally known figure — and a political lightning rod. It culminated in a lost election last year and conviction for criminal contempt in July.

Mr. Arpaio has been in the headlines for decades, and he grabbed another Friday when President Trump pardoned him — to the sound of outraged Democrats (and muted Republicans).

Here is a guide to The New York Times’s coverage of Mr. Arpaio’s career.