Michael R. Bloomberg, founder of Bloomberg LP and Bloomberg Philanthropies, served as mayor of New York from 2002 to 2013.

Over the course of the 2020 Democratic presidential campaign, candidates have been asked time and again to explain — often, in about 30 seconds — what they would do on a broad range of critically important issues, from climate change and gun violence to health care and taxes. And yet rarely are the candidates asked, and more rarely still do they talk about, how they would go about achieving their goals.

The president of the United States runs the executive branch, with its hundreds of agencies and 4 million employees. The job’s essential skills primarily involve leadership and management, not policy analysis. The country elects a commander in chief, and yet based on the campaign so far, one might think we are electing a legislator in chief — or a prime minister whose party controls a parliament.

In reality, the next president is likely to face a closely divided Congress. Winning passage of legislation, whatever its details, will require a mix of compromise and cajoling, horse-trading and arm-twisting, favor-granting and trust-building. Yet candidates speak as though the power of the bully pulpit will be sufficient to overcome opponents. It won’t, as recent history makes abundantly clear.

The fact is: A legislative proposal is only as good as the execution plan that accompanies it. And even the best plans must be flexible enough to accommodate necessary changes, to prevent the perfect from being the enemy of the good.

Candidates can promise the whole loaf. But executives need to figure out how to get at least half. Or as my old friend, former New York governor Mario Cuomo, often said: “You campaign in poetry; you govern in prose.”

The only time I’ve spoken with President Trump in recent years was in the weeks after the 2016 election, when he asked me for my advice on governing. I was blunt. I told him: You don’t know anything about government. Hire people who are smarter than you.

I didn’t say it to be insulting. I had been in a similar spot 15 years earlier. I spent my career in the private sector before being elected mayor of New York in 2001. After the election, I knew enough to know I didn’t know much, and I needed to hire experts to run city agencies, give them the freedom to innovate and hold them accountable for producing results. In both the public and private sector, micromanagement — and believing you are the expert on all things — provide the surest path to failure. Everything that our administration accomplished in New York over 12 years was a reflection of the people I was able to attract into those jobs.

The president did make a few good hires, such as retired Marine Gen. Jim Mattis. But mostly he hired cronies, ideologues and sycophants, while also leaving hundreds of important senior level positions unfilled and paying less attention to many agencies than he does to cable TV news. It’s no wonder the administration has been defined by chaos, incompetence, corruption and — most recently — acts that have prompted an impeachment inquiry.

The tragedy is that all this stands in marked contrast to the important and impressive work that talented and dedicated federal employees do every day. Many are frustrated by the lack of leadership and support they receive, including those who have seen the administration attempt to undermine scientific integrity. And yet the overwhelming majority continue to do outstanding work.

On Wednesday, I will attend the Samuel J. Heyman Service to America Medals gala in Washington, hosted by the staunchly nonpartisan Partnership for Public Service, celebrating six federal employees who have made especially large contributions to the public good. One of them, Victoria Brahm, works at a Veterans Administration Medical Center in Tomah, Wis. The facility had formerly so overprescribed opioid painkillers that it was nicknamed “Candy Land.” Because of her work, the center has gone from being one of the worst in the country to one of the best. And use of opioids and other prescription painkillers among patients has declined by 67 percent.

With so much rancor in politics today, public servants such as Brahm remind us of the power of the federal government to do good — and the importance of electing people capable of leading and managing it. Yet none of the two dozen or so Democratic presidential candidates plan to attend the event. No president has ever attended.

It should not be too much to expect the nation’s chief executive to attend the nation’s premier event honoring federal employees. And if the Democratic candidates won’t commit to going next year, it says a lot about their understanding of what real leadership and strong management entails.

The presidential aspirants are not short on big ideas. But voters must demand they explain how they intend to move from proposing plans to actually implementing them, including passing them through Congress. Those who dodge the question by speaking of revolution and the bully pulpit aren’t up to the job.

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