Because Donald Trump is so obviously a flawed candidate, he allows Republicans and conservatives to spend yet another election cycle learning nothing from the past 15 years. He allows Republicans to continue denying one of the great and unacknowledged political truths of our time: Barack Obama is president today because George W. Bush took our nation to war in Iraq.

History keeps conspiring to hide from Republicans the fact that Americans no longer trust their party to conduct foreign policy. It threatened to dawn on them after the electoral "thumpin'" they took in 2006. It might have occurred to them when the diminutive libertarian crank from Texas, Ron Paul, began raising millions of dollars and placing well in 2008 contests. But everything went according to plan and the GOP nominated the experienced hawk, John McCain, in 2008. When he lost, they attributed his defeat to either Sarah Palin's incompetence or Barack Obama's speechifying (which they overrated). After that the Republicans received a boost in the arm from the midterm elections of 2010. The Tea Party may have brought some cranks into the House, but it demonstrated that they were not so unpopular after all. That's true, even though four years after the Tea Party comeback, 71 percent of Americans said the Iraq War wasn't worth it.

Trump has criticized the Iraq War, and claims to have opposed it at the time. (He didn't.) While he has occasionally styled himself as a devotee of "America First" restraint in foreign policy, refusing to keep America in its role of global sheriff, he has also occasionally played the role of super hawk, vowing to "take the oil" from America's Middle Eastern foes.

Conservatives who have opposed Donald Trump most loudly have framed their opposition to him as one of the great moral stands of our time. To be against him is to be on the side of decency, morality, and the future. To join with him is the abyss. How convenient for them that their lives will be defined by their refusal to cast a ballot, not their vociferous support of the worst foreign policy disaster since the Vietnam War.

There is no evidence that the top minds among elected Republicans have dedicated even a passing thought to the trust they've lost on foreign policy. Even at the beginning of the campaign, it was astonishing to watch a seasoned governor from America's prominent political family evince no preparation at all for questions about the Iraq War, his brother's mean governing legacy to the world. Jeb Bush even seemed unaware that his brother had voiced regrets for the war.

And because there is no thought, the political instincts of the Republican Party are completely unmodified from the 1970s. The GOP's habit is to kick the Democrats for being feckless doves. But this habit only makes the party seem ever-more disconnected from reality. Consider the endlessly repeated Republican talking point that the Syrian civil war is a disaster because President Obama failed to enforce his "red line." The truth is that it was Republicans who, when they had the chance to endorse harsh measures against Syrian President Bashar al-Assad, backed away in deference to overwhelmingly dovish public opinion.

The third-party challenge of Evan McMullin is emblematic of the Republicans' professional foreign policy caste. He is a former CIA man. He has all their habits and social cues: He tells you that he is tolerant and solicitous of America's minorities, even as he campaigns almost exclusively in the white Mountain West. He is polished and prepared. He respects political conventions. McMullin also repeats the utterly bonkers Republican talking point that Obama has "withdrawn" American power from the world stage. This despite the fact that America is running military operations in the air and on the ground in Syria, Iraq, Libya, Yemen, Afghanistan, and Somalia. He advocates a no-fly zone over Syria, one that would obviously lead to American responsibility for the ultimate outcome of that nation's civil war, and could potentially mean direct military conflict with Russia. And conservative activists and pundits call this moral seriousness.

Donald Trump is pulling his money away from the campaign. He is blaming his party as he heads toward defeat. He may take the Republicans' Senate majority down to defeat with him, and he will seriously damage the Republicans' congressional majority. But he will have performed one great service for the party: He will allow its mandarin class to keep their delusions for four more years.