Imagine an autopsy that concludes the cause of death was a drug overdose. After the funeral, distraught family members assemble to talk about how they could have prevented such a senseless tragedy. Then, after brief reflection, they all decide to start mainlining heroin.

That, in a nutshell, is the history of the Republican Party over the past half-century.

The GOP is addicted to whiteness, a psychological drug it started ingesting in the early 1960s with the encouragement of Goldwater conservatives, who argued that the party could win over the traditionally Democratic white South by resisting the civil rights movement. Richard Nixon was one of the Republicans who initially had trepidations. “If Goldwater wins his fight,” he told Ebony magazine in 1962, “our party would eventually become the first major all-white political party. And that isn’t good. That would be a violation of GOP principles.”

Nixon was right. But like most party leaders, he soon came around to the Southern Strategy, crafting a set of coded appeals to white resentment that helped him win the White House in 1968 and 1972. If Goldwater was the GOP’s original dealer, Nixon was its first full-blown junkie.

Like any decent recreational drug, whiteness initially made the Republican Party feel good. It fueled a swing to the right that picked up many disaffected whites unhappy with the Democrats’ embrace of civil rights. Following Nixon, it powered the national victories of Ronald Reagan and the George Bushes. But over time, the very drug that made the Republican Party so powerful slowly started to kill it.