What does Trump actually want to do as president? The answer is unclear.

There are many, many frustrating elements to this administration. But perhaps the most basic is that it’s not easy to figure out what Donald Trump actually wants out of the presidency.

Most presidents have multiple goals for the office:

Only the last clearly matters to Trump. Otherwise, his behavior doesn’t seem to make sense in pursuit of any of these goals.

Accomplish the policy objectives of their party. Probably the strongest predictor of presidential behavior is political party. Democrats and Republicans tend to act in systematically different ways. That has been more true since about 1980, in the era of what I have called the “partisan presidency.” Trump would seem to be an exception to this pattern. He was a newcomer to Republican politics. Few party “insiders” supported his candidacy, and even after he won the nomination, many top Republicans seemed distinctly cool to the prospect of him as president. He was all over the map on issues: sometimes vague, sometimes centrist, sometimes populist, sometimes conventionally conservative.

As president, Trump has mostly pursued Republican policies: repeal of the Affordable Care Act, lower taxes, conservative judges, rollback of environmental regulations. There has been little movement on more centrist objectives such as infrastructure. As a candidate, Trump sometimes sent signals that he might be more secular and less socially conservative than other Republicans. But as president, he’s been more loyal to the religious right than arguably any other constituency.

But Trump doesn’t seem able or willing to try to accomplish these goals. He has purged the White House of most figures with good relationships with congressional Republicans. He did little to help Republicans pass Affordable Care Act repeal, but then denounced them for giving up after passage failed in the Senate. (He gets along with Democrats even less.) Trump seems more committed to pointless feuds than to achieving policy ends.

Accomplish their own policy objectives. While most presidents pursue partisan policy goals, they usually have their own aims as well. At times, Donald Trump has espoused a nationalist/populist/authoritarian agenda on immigration, trade, law enforcement, and foreign policy. This worldview sometimes embraced a more interventionist approach to the economy. Much of this program has been discarded or placed on the back burner.

But Attorney General Jeff Sessions has been the most effective figure in accomplishing Trumpist goals. He was the first prominent elected Republican to endorse Trump. He embraced restrictionist views on immigration before Trump himself did. He has filled the Justice Department with reasonably capable appointees. He is pursuing a Trumpist agenda on immigration, affirmative action, voting rights, and law enforcement. How has Trump repaid him? By abusing and humiliating him.

Win reelection. Trump is quite unpopular (and becoming more so), and he doesn’t seem interested in changing that. He has doubled and tripled down on appealing to his base. He has conducted little outreach to Democrats or swing voters. Most of the policies he backs are unpopular. He is also personally disliked. He enjoys his strongest ratings on the economy, which is one area where he has done little while benefiting from the good luck of inheriting prosperity. If Trump were more concerned with seeking broad popularity, he would have steered a centrist course on health care, shut down his Twitter account, and become far more restrained in his public statements. He has not done any of these.

“Public service.” Since George Washington, some presidents seem to have been motivated mostly by a sense of public service — Dwight Eisenhower and George H.W. Bush fall into this category. It’s safe to say that Trump does not.

Lead the nation in crisis. Many of the presidents of the Cold War era sought to lead the nation during a time of crisis. As with the economy, Donald Trump has been lucky to take office in a relatively tranquil era. He does face foreign policy challenges in North Korea and Syria. But he appears more concerned with his personal grievances.

Build power. Whatever else presidents do, they must amass power. This can go well beyond the formal powers granted by the Constitution. As Richard Neustadt wrote in Presidential Power and the Modern Presidents, “presidential power is the power to persuade.” Presidents need to gain the assistance of other actors both in and outside of government. But Trump instead seems bent on alienating every other power center in Washington. He could turn to the executive branch as a source of power. But with a few exceptions, he has not. He has failed to fill vacancies, and his antics must discourage potential appointees. He browbeats career civil servants but rarely follows through on his rants.

Trump could serve as a negative example supporting Neustadt, showing what happens if you do not care about your reputation with other political actors, and if you show little interest in bargaining with them.

Boost his ego. Most presidents are highly ambitious. Many have had streaks of vanity, such as Richard Nixon, who briefly dressed White House guards in garish outfits patterned after their European counterparts. But Trump seems more obsessed with this part of the job than his predecessors. I once noted that Trump’s presidential bid seemed like an exercise in consumption — the campaign itself was its own reward. Much the same could be said of the Trump presidency.

The previous motives could apply to most previous presidents. But there are two that are (mostly) unique to Trump:

Enriching himself. Donald Trump really is unique among presidents in the degree to which he seems uninhibited in his desire to use the presidency to enrich himself and his family. (Plenty of ex-presidents, most notably Gerald Ford and Bill Clinton, have made millions after leaving office. But that doesn’t seem to have motivated their behavior during their presidencies.)

Staying out of jail. Alas, Donald Trump is not the only president for whom this is a major goal. The last year of Richard Nixon’s presidency was consumed with the quest to hold on to the presidency or, at the very least, keep himself out of the clink.

So what has Trump been about in the first half of his first year as president? Mostly about Trump. His policies have been more conventionally Republican than expected, but he does not seem especially motivated in trying to accomplish substantive goals. The appointment of John Kelly as White House chief of staff indicates that Trump might be seeking to become more effective. But to what end?