An unlikely voice recently bemoaned the decline of civility in presidential politics, warned that “deep anger” was fueling an “almost radical populism” and sang the praises of former President Bill Clinton — particularly his “redemptive” years of philanthropic work since leaving the White House.

The voice was that of Kenneth W. Starr, the former Whitewater independent counsel, whose Javert-like pursuit of Mr. Clinton in the 1990s helped bring a new intensity to partisan warfare and led to the impeachment of a president for only the second time in the nation’s history.

The presumptive Republican presidential nominee, Donald J. Trump, increasingly seems to be trying to relitigate the scandals that Mr. Starr investigated, dredging up allegations of sexual transgressions by Mr. Clinton to accuse Hillary Clinton — the likely Democratic nominee — of having aided and enabled her husband at the expense of Mr. Clinton’s female accusers.

But Mr. Starr expressed regret last week that so much of Mr. Clinton’s legacy remained viewed through the lens of what Mr. Starr demurely termed “the unpleasantness.”