It has been a long and unproductive year for President Donald Trump. Repealing and replacing the Affordable Care Act cratered. The wall on the U.S.-Mexican border hasn't been built or even funded. Tax reform, though moving forward, is still well short of a Rose Garden signing ceremony. Despite unified Republican control of government, he's got little to show for it.

Yet it has also been a long and quite productive year for the president. He has dramatically changed the direction of federal policy toward the environment, the energy industries, immigration, education, civil rights, trade and the federal workforce, and he is rapidly remaking the federal court system. What former President Barack Obama started in many of these areas, Trump has started to reverse.

The president's tweets draw outsized attention to his grievances and his petty feuds. The absence of notable legislative successes focuses criticism on his style of leadership. Those realities overshadow what he has and is doing unilaterally, to the extent of his executive powers. In other ways, his presidency seems unique. In the arena of executive action, he is pursuing a model established by his recent past predecessors, with worrisome consequences to constitutional governance.

That's the conclusion of an essay in the most recent issue of the Forum, a nonpartisan journal of ideas and political analysis. Sidney Milkis and Nicholas Jacobs, both of the University of Virginia, argue that Trump's deployment of what they call "executive-centered partisanship" is both in keeping with the modern presidency and a potentially damaging shift in our politics.

The authors take note of Trump's acceptance speech at the Republican National Convention, where he said that he, an outsider, knew better than anyone how to solve the problems of broken government. "Nobody knows the system better than me," he said. "Which is why I alone can fix it."

The first year of his presidency appears to make a mockery of that statement, given the problems he's had in Congress and the fact that his approval ratings are the lowest of any president at this point in his term as far back as there was polling.

Yet, as the authors note, "Often overlooked among the disappointments and recriminations of Trump's frenzied beginning is his administration's aggressive and deliberate assault on the Liberal state. ... Since day one, Trump has forcefully - and sometimes successfully - taken aim at the programmatic achievements of his predecessor."

Milkis and Jacobs contend that this approach to governing has its roots in presidencies dating back decades. The consequence is the evolution of a "presidency-centered and rancorous contest between liberals and conservatives" with all kinds of collateral damage to Congress, the states and public trust and confidence in government overall.

They argue that this has produced a politics that is "no longer a struggle over the size of the state" but instead is a contest between liberals and conservatives "to seize and deploy the state and its resources."

Former Presidents Ronald Reagan and George W. Bush used these powers to advance conservative objectives. Obama, the authors note, campaigned as someone who would move the nation past mindless bickering to a post-partisan presidency, but in office, particularly as his frustrations with a Republican-controlled Congress intensified, fully embraced the use of vigorous executive action for political and partisan ends.

"Most of his executive actions were directed to strengthening a widely scattered but potentially powerful coalition that had been forming since the Great Society: minorities, youth, the LGBTQ community and educated white voters, especially single women," according to the authors.

Though the goals of Obama's and Trump's uses of executive action are diametrically opposed politically, the authors contend that the two presidents share two things in common: "a detachment from party organization and a vision of the White House as the vanguard of a movement."

Trump has lacked a clear legislative strategy from the start of his presidency. He had no well-developed policy proposals to offer the Congress, he lacked interest in learning the details of key legislation such as health care, he has shown limited interest in using the bully pulpit to advocate for the GOP's legislative priorities and, though he has spent considerable time talking with legislators, he has not demonstrated that he is the kind of dealmaker he claimed he would be.

In the area of executive action, however, he has pursued goals consistent with his campaign rhetoric - and like Obama, priorities designed to appeal directly to his own political coalition.

Some actions hue closely to conventional conservative Republican doctrine. Others reflect his "America First" perspective and a suspicion of what former adviser Stephen Bannon called the "deep state" of the federal bureaucracy. At times, he has pursued actions that concern some elements of the traditional Republican coalition. At other times, he is acting in pursuit of the goals of that coalition.

There can be no final accounting of success or failure in this arena, given the short time Trump has been in office and the obstacles that exist in the face of a president attempting to act unilaterally.

So far the record is mixed. Trump has moved policy in a different direction, but Milkis and Jacobs write that, in the immediate term, his actions seem to have "fostered a destructive working arrangement in the White House Office, the hollowing out of regular departments and agencies and limited his support to conservative Republicans who represent roughly 40 percent of the electorate."

The authors close with a note of warning. What began in other presidencies has become "a glaring alarm during Trump's presidency." That is the "false illusion" that the executive "can truly function as a representative democratic institution." Instead, they say, executive partisanship exposes the public to leaders who scorn institutional restraints that are a vital ingredient of constitutional government" as well as the collaboration that long has been at the core of party politics.

The president and Congress face a busy and potentially fateful month of legislative conflict, which will legitimately be the focus of attention through the end of the year. But no one should lose sight of the unilateral action at the other end of Pennsylvania Avenue that has been every bit as defining in the record of Trump's presidency.