Unfinished rules, however, are the easy prey. Cutting three-quarters of the 90,000 federal regulations already on the books is sheer folly. To roll back even one rule requires a whole new rule-making procedure — writing a draft rule, taking public comment, writing a final rule, more comment, and so on — that takes many months. The process, while imperfect, is designed to prevent a president or Congress from capriciously slashing regulations which, after all, were created to protect Americans, their workplaces and environment.

Mr. Trump’s team, aiming to undo Mr. Obama’s environmental record, has targeted a lot of important stuff — greenhouse gas regulations for power plants, fuel economy standards for cars and trucks, a long overdue rule updating the Clean Water Act. But Mr. Trump cannot eliminate or even modify these rules with the simple stroke of a pen.

As for the federal hiring freeze, this, too, has been tried before, with uncertain results. Presidents Carter and Reagan both learned that while a sweeping freeze looks like common-sense budget-cutting, it can actually cost money. President Carter froze full-time hiring three times, so agencies simply hired more part-timers, temps and contractors. As a result, federal employment actually rose during two of the three freezes. Using an ax rather than a scalpel, across-the-board hiring freezes target all agencies regardless of workload or mission. Between 2010 and 2014, for instance, staff reductions at the Internal Revenue Service held up tax enforcement and collection, costing the government $2 billion in revenue in 2015.

Can Mr. Trump do better? The prospects are poor. He appears to have little understanding of how the federal government is organized and functions, and his skeletal staff is still trying to learn. He hasn’t yet appointed people to lead most of the agencies affected by these changes, and his “beachhead teams,” 600 people who began meeting with federal agencies last week, have so little government experience that they can’t provide much guidance.

Mr. Trump relishes his boldface proclamations. “President Trump Takes Action,” his news releases say. He’s been signing his executive orders on TV, holding them up and explaining them aloud, like story hour in the Oval Office. Maybe these pledges will actually streamline government in a positive way, instead of undermining it, as the ideologues around the president seem to want. But so far, they are mainly show.