The rise of Mr. Trump and his brand of racial populism has undermined nearly all the report’s recommendations on minority outreach. Among black voters, 90 to 94 percent hold unfavorable views of the nominee. By current polling accounts, he is winning between 4 to 9 percent of the black vote. Sally Bradshaw, one of Jeb Bush’s top advisers and a co-author of the 2013 report, recently announced that she was leaving the party, citing Republicans’ decision to nominate “a bigot.”

And yet, when you look beyond such glossy items like that 2013 report, the damage done by Mr. Trump feels of a piece with the party’s history, however much people like Ms. Bradshaw protest. Set aside the instances of racial demagogy; even at its best moments, for decades the party has been unable to move beyond broad assessments and platitudes to advocate substantive change.

The party has had no shortage of analyses devoted to fixing its “race problem.” In 1939, the future Nobel Prize winner Ralph Bunche created a blueprint for winning over black voters. Dozens of reports followed, usually in the aftermath of a disastrous presidential loss. After the 1964 presidential election, when the Republicans garnered only 6 percent of the black vote, a group of former Goldwater supporters concluded that the party could no longer rely on “racist appeals, overt or covert.”

But as with the past four years, whenever the party begins to make incremental gains in its relationship with African-Americans, it finds itself pulled to the right, often at the expense of black needs and interests. In 1960, Richard M. Nixon won 32 percent of the black vote; in 1962, he told Ebony that it would be foolish and a “violation of G.O.P. principles” to give up on black voters. By 1968, as the Republican presidential nominee, he had alienated African-Americans with his racially charged language of “law and order.”