Sceptics might rationalise that Mitt Romney received a scant 6 percent of the black vote in 2012 only because African Americans would naturally favour one of their own. But since 1964, no Republican presidential candidate has attracted more than 15 percent of the black electorate, and few GOP candidates for other offices have fared much better. No segment of the American electorate is more reliably Democratic than African Americans. The GOP, meanwhile, remains nearly an all-white party.

In this path-breaking book, historian Timothy Thurber illuminates the deep roots of this gulf by exploring the contentious, and sometimes surprising, relationship between African Americans and the Republican Party from the end of World War II through Richard Nixon’s presidency. The GOP, he shows, shaped the modern civil rights movement, but the struggle for racial equality also transformed the GOP.

Thurber challenges conventional wisdom that the “party of Lincoln” disappeared in the mid-1960s. Prior to 1964, the GOP was indifferent or hostile to many of the demands from civil rights activists. During the height of the civil rights revolution, Republicans were essential to enacting federal policies that made American society more egalitarian. The GOP helped defend, and sometimes expanded, those reforms in the early 1970s. Conservatives were not as dominant after 1964 as scholars and pundits often portray.

Yet throughout these three decades the rift between African Americans and the GOP remained substantial. They disagreed, often sharply, over the role of the federal government, particularly regarding economic matters and the integration of schools and neighbourhoods. They had different views about race and American society. They also clashed in the political arena, where Republicans wrote off the black vote as unwinnable, irrelevant, or counterproductive to their drive to supplant the Democrats as the nation’s majority party. The GOP preferred to court whites nationwide, sometimes by appealing to their racial animosities.

That strategy often yielded electoral success, but the legacy of the past looms large in the early twenty-first century. With its depth of research and insight, Republicans and Race will stand as a definitive study as the GOP ponders the composition of its base in future elections.