The Twitter symbol appears above its trading post on the floor of the New York Stock Exchange. (Richard Drew/Associated Press)

All political leaders, presidents in particular, dream of using technology to avoid the media filter and speak directly to the American people.

Thomas Jefferson — both eloquent founder and appalling political hack — weaponized the pamphlet, commissioning scandalmonger James Callender to write a hit job on Alexander Hamilton. Warren Harding pioneered the political use of radio, which was perfected by Franklin D. Roosevelt, whose ambitions were aided by having a good radio voice. Not everyone was a fan of the medium. When a radio microphone was put in front of diplomat Elihu Root, he is said to have responded: “Take that away. I can talk to a Democrat, but I cannot speak into a dead thing.”

John F. Kennedy’s political appeal was unimaginable without televised images of his youth, vigor and physical grace. Ronald Reagan talked to the camera like an old, single-eyed friend.

But no president has really possessed the technical means to routinely avoid edited, moderated mass communication until now. President Trump holds his office, in part, because of his talent for Twitter. He has shown a remarkable ability to dominate the news cycle and redirect the national conversation in increments of 140 characters. For Trump, this medium is a living, snarling and hungry thing.

Make no mistake: This is not only change, it is regression. I make this judgment both as a fogey and a former speechwriter. A presidential speech may be two thousand or three thousand words, every one of them run through the staffing process (in which senior White House officials can comment), fact-checked and approved by the president before delivery. A good presidential speech is the result of both thought and craft. A great presidential speech reflects literary, historical and moral inspiration and can speak far beyond its moment.

I understand the usefulness of social media in aggregating flows of information that people trust, enjoy and need. It allows people to essentially be their own editors (the value of which is determined by the news literacy of the user). And some people have a remarkable knack for communicating in vivid fragments. Pope Francis (with 10 million Twitter followers) distributes bits of wisdom and comfort like virtual communion wafers. Katy Perry (with more followers than the population of Germany) says, well, whatever it is that Katy Perry says.

But in politics, Twitter has dramatic limits and can become a disturbing substitute for disciplined thought.

One hundred and forty characters are suitable to expressing an impulse, but not an argument. It is the rhetorical equivalent of a groan, a shriek, a sneer or a burp. If reason and persuasion are what our politics lacks and needs, Twitter is not the answer.

Trump’s mastery and extensive use of Twitter are revealing in a way he does not intend. This is the only area in which Trump can be considered a great communicator. His stump speech was a disorganized, repetitive, unfocused mess. His inaugural address was memorable only in ways — such as its dark, shrunken view of the United States itself — that deserve to be forgotten. His recent speech at the CIA was strangely inappropriate and offensive. So he often returns to the comfort zone of Twitter. He claims Hillary Clinton lost in a “landslide,” or goes after a specific news organization, or makes entirely unsubstantiated claims of voter fraud.

Some feel that journalism would be better served by ignoring such shiny objects. But the shallowness of Trump’s preferred form of communication indicates deeper things. His mind seems perfectly suited to a medium that rewards impulsiveness, that ignores fact-checking and that encourages incivility. Those are not generally the traits we hope for in a new president.

And Trump’s use of Twitter raises the prospect of a serious abuse of power. A private citizen with 22 million followers (as Trump has) can be a vindictive jerk, attacking the owner of the Chicago Cubs, the head of the United Steelworkers or a Gold Star family by name. A president with 22 million followers, including the shock troops of Internet bullying, can destroy an individual’s life as surely as can targeting by the FBI or the IRS.

At moments of frustration, Trump will be sorely tempted to attack specific people on Twitter. But a government official should not be allowed to take the reputation or peace of any citizen without due process. It is the president’s job to enforce laws without distinction, not to choose specific men and women for harm. This would be the practice of personal rule, and a scary detour toward Putinism.

Read more from Michael Gerson’s archive, follow him on Twitter or subscribe to his updates on Facebook .