Wait, there’s more: Incredibly, Mr. Bush resorted to the old passive-voice dodge, admitting only that “mistakes were made.” Indeed. By whom? Well, earlier this year Mr. Bush released a list of his chief advisers on foreign policy, and it was a who’s-who of mistake-makers, people who played essential roles in the Iraq disaster and other debacles.

Seriously, consider that list, which includes such luminaries as Paul Wolfowitz, who insisted that we would be welcomed as liberators and that the war would cost almost nothing, and Michael Chertoff, who as director of the Department of Homeland Security during Hurricane Katrina was unaware of the thousands of people stranded at the New Orleans convention center without food and water.

In Bushworld, in other words, playing a central role in catastrophic policy failure doesn’t disqualify you from future influence. If anything, a record of being disastrously wrong on national security issues seems to be a required credential.

Voters, even Republican primary voters, may not share that view, and the past few days have probably taken a toll on Mr. Bush’s presidential prospects. In a way, however, that’s unfair. Iraq is a special problem for the Bush family, which has a history both of never admitting mistakes and of sticking with loyal family retainers no matter how badly they perform. But refusal to learn from experience, combined with a version of political correctness in which you’re only acceptable if you have been wrong about crucial issues, is pervasive in the modern Republican Party.

Take my usual focus, economic policy. If you look at the list of economists who appear to have significant influence on Republican leaders, including the likely presidential candidates, you find that nearly all of them agreed, back during the “Bush boom,” that there was no housing bubble and the American economic future was bright; that nearly all of them predicted that the Federal Reserve’s efforts to fight the economic crisis that developed when that nonexistent bubble popped would lead to severe inflation; and that nearly all of them predicted that Obamacare, which went fully into effect in 2014, would be a huge job-killer.