Political scientists will tell you that we spend too much time worrying about personality in politics. All those stories in every presidential campaign—about the advice one candidate's grandpappy gave him down at the fishin' hole or what the other candidate's taste in music says about her—they're mostly irrelevant. What matters much more, not just for how elections turn out but for what happens between them, is larger, broader forces and institutions: the state of the economy, durable electoral and policy coalitions, the nature of partisanship, and so on. The personal stuff might be interesting, but its effects are only seen at the margins.
In some ways, those buzzkilling political scientists doing their best to render politics dry and uninteresting are unquestionably correct. Impersonal forces have enormous effects, and the further back you set your view, the less the day-to-day decisions of individuals seem to matter. But this is 2017, and Donald Trump is the president of the United States. So now, everything's personal.
Let's take what happened this weekend as an illustration. For some reason, on Sunday morning Trump went on a little Twitter tirade about Senator Bob Corker of Tennessee, who recently announced that he won't be running for re-election. "Senator Bob Corker 'begged' me to endorse him for re-election in Tennessee. I said 'NO' and he dropped out," Trump tweeted, adding that Corker "is also largely responsible for the horrendous Iran Deal!" (An odd claim, since it was negotiated by the Obama administration, along with China, Russia, Germany, France, Great Britain, and the European Union.) He finished up by saying that "I would fully expect Corker to be a negative voice and stand in the way of our great agenda. Didn't have the guts to run!"
In that tweet, Trump certainly puts his finger on something interesting. If your agenda was dependent on a narrow 52-48 majority in the Senate, and you had already lost a couple of high-profile votes because of a few defections, and at least one of those defections came from a senator you had personally insulted multiple times, why would you want to attack Corker, when he'll be in office for another 15 months, a period where some critical legislation will be considered?
Corker reacted by tweeting, "It's a shame the White House has become an adult day care center. Someone obviously missed their shift this morning," which will almost certainly enrage the president and lead him to escalate the conflict. Then what happens when Trump needs Corker's vote on some upcoming legislation? The idea of humbling the president who insulted him could become awfully attractive. That surely played a part in John McCain's thinking when he decided to provide the last vote killing the GOP's shambolic effort to repeal the Affordable Care Act. After watching Trump question his Vietnam service, McCain—not above some personal vindictiveness himself—no doubt found the idea of making Trump seethe to be at the very minimum a fringe benefit of his "no" vote.
The GOP health-care effort was a disaster from the start, but the fact that it lost by the narrowest of margins shows that no outcome is guaranteed. If some standard-issue Republican were president—a Marco Rubio or a John Kasich—would we be marvelling at the fact that nine months into their total control of Washington, Republicans had failed to pass a single significant piece of legislation? There are many reasons why that has happened, not least the stunning lack of preparation they did for this moment and the internal divisions within their party. But at every turn, Trump has made their task harder by alienating members of Congress and making public promises they have no intention of keeping.
Despite his belief that he's a master dealmaker, Trump has shown himself utterly incapable of the things Washington dealmaking requires, including mastering the issue at hand and building and managing relationships with members of Congress whose own interests are often in conflict even within each party. So the agenda flounders, and one major issue after another winds up being shaped by Trump's personal whims and resentments. For instance, the administration is trying to find ways to sabotage the Iran nuclear deal, despite the fact that according to multiple reports, all of Trump's national security aides believe the deal is accomplishing its purpose and we should stay in it. But Trump hates it, for little apparent reason other than the fact that it came from Barack Obama. (I'm fairly certain that if you asked Trump what his specific objections are, he wouldn't be able to tell you.) So it's entirely possible that the the United States will pull out of the deal, it will collapse, and Iran will resume its efforts to acquire nuclear weapons.
And of course, his own secretary of state believes Trump is a "moron," and the controversy over that revelation has left the United States effectively without a top diplomat, or at least one anyone in the rest of the world can trust to speak for his boss. Trump distrusts Tillerson because, according to The Washington Post, "Trump believes his top diplomat often seems more concerned with what the world thinks of the United States than with tending to the president's personal image."
That's one of those reports about Trump that manages to be simultaneously gobsmacking and unsurprising. For this president, everything is personal. The purpose of the State Department isn't to represent the United States to the world but to tend to Trump's personal image. Anyone who criticizes him becomes an enemy. There is no substantive agenda beyond what will lead to the greater aggrandizement of Donald Trump. Perhaps that's what one might have expected from someone who made a career creating and monetizing a personal brand in which the central message was his own fabulousness, but it's still shocking to witness.
The bargain Republicans made when they decided to support Trump was that his personality could be, if not quarantined, then at least compartmentalized. Sure, he'd say offensive things and start inane fights, but the work of politics could go on almost without him. They'd get their tax cuts, their abortion restrictions, their corporate giveaways, their attack on the safety net, and all rest of it, while he occupied the media's attention with his antics. There are some ways in which that has indeed happened; Trump probably neither knows nor cares about the horrors going on at the EPA or the Department of Energy, and he hasn't stood in the way of Republicans undoing years or decades of progress.
But he's also showing just how much the personality of the president matters. By the time this presidency is over, there will without doubt be a string of world-shaping failures in which his personality, more than anything, determined what occurred. And over and over again, we'll marvel that only Donald Trump could have screwed things up so badly.