President Trump said his new chief of staff John Kelly will do a "tremendous job," after his swearing-in on July 31. "We have a tremendous group of support, the country is optimistic and I think the general will just add to it," Trump said. (The Washington Post)

Six months into his presidency, President Trump has just pulled retired general John F. Kelly away from his position heading Homeland Security to be his White House chief of staff.

As a result, Trump has one more agency run by an acting head. In fact, Trump has had only 50 nominees confirmed by the Senate, out of the 575 key policymaking positions it’s his responsibility to fill. For another 600-plus Senate-confirmed positions he’s supposed to fill — including ambassadors, U.S. attorneys, U.S. marshals, officials on boards and commissions — he’s been even slower.

How does Trump’s appointments record compare to that of his predecessors? According to data from  The Washington Post and the Partnership for Public Service, President Barack Obama had filled 228 of his key policymaking positions by this point in his first year.

Of course, these offices aren’t actually empty. Individuals are handling virtually all those responsibilities in a temporary or acting capacity. If experienced career professionals fill the “vacant” jobs, do the vacancies matter?

Do vacancies hurt the president’s agenda?

Most scholars of the administrative presidency would agree that if a president wants to control public policy, he wants his appointees in place. Federal agencies make decisions every day about how to interpret statutes, spend funds appropriated by Congress, and enforce federal laws. These decisions affect policy in ways that can be more important than the laws on which they’re based.

Further, government executives get involved in formulating executive orders and legislation. That’s why most presidents first focus on filling the appointed positions related to their hoped-for legislative agenda. Trump, for example, nominated Seema Verma early on to lead the Centers for Medicare and Medicaid Services, the agency that’s central to implementing the Affordable Care Act.

At the moment, however, key positions in tax policy, immigration, and infrastructure remain vacant. This leaves the president shorthanded. An understaffed and inexpert White House must do all of the policy and public relations work that could be done by the president’s appointees.

With many top-tier posts still empty in President Trump's new government, cabinet secretaries are getting exasperated with the lack of senior-level staff in their agencies. (Jenny Starrs/The Washington Post)

Career civil service professionals who are temporarily handling these jobs realize that, under the Constitution, they work for both the president and Congress. They don’t have either the political support nor the leverage to push the president’s agenda. Federal agencies often wait until a nominee is confirmed before making any big decisions, lest these be decisions reversed once a nominee takes the reins. Even when acting officials want to implement important initiatives, they are resisted by agency employees who realize they’re short-timers.

It’s hard for the president to effectively communicate his priorities to 2.85 million federal employees when most of those still work in agencies without presidential appointees.

Do vacancies affect government performance?

This is a difficult question to answer. It’s hard to measure government performance systematically — because observers don’t agree on what counts as “good performance.” For instance, does good EPA performance mean more regulations or fewer? And it’s hard to compare executives and agencies against one another because, serving under different presidents, they have different mandates, operating environments, and political constraints. However, researchers do have some evidence — and can make a few generalizations about how vacancies affect performance.

First, giving career executives more authority can actually help make agencies run more smoothly. In research during the George W. Bush administration, I studied the management performance of programs and agencies run by career executives versus those run by political appointees. Programs and agencies run by career executives earned higher management scores than those run by political appointees — largely because career executives had on average spent more time in top jobs and better understood the organizations they were managing. Knowing the players, the institutional levers, the statutory and political limits, and so forth made it easier for career executives to manage effectively.

But the benefit of this professionalism is counteracted by acting officials’ term limits. Acting officials face statutory limits in how long they can serve. Usually, they may serve 210 days as an acting agency head without anyone being formally nominated for that position; at the start of a new administration, acting officials get an extra 90 days beyond that.

Currently, 360 people are serving in high level positions with no formal nominee. By mid-October, these acting officials will have to leave unless the president speeds up the pace of nominations. This guarantees regular turnover among short-timers in each agency, unless the president gets appointees nominated and approved. More turnover leads to performance problems because of leadership vacuums, mixed signals about agency goals, and an inability to credibly commit to any long-term policies.

Vacancies at the top also leave staffers confused about their agency’s goals and unable to mobilize resources and support. In the research mentioned above, programs run by appointees had clearer goals and designs than programs run by career managers. Appointees were more likely to have White House or congressional experience; that correlated with clearer agency goals and designs.

Perhaps most important, acting officials don’t have the credibility to persuade other government officials to do what is necessary to help make policies succeed. Virtually all government work involves more than one agency. Successfully implementing a policy can require the cooperation of local, state, federal, and even international officials. Persuading them to sign on to a policy is more difficult if an official doesn’t have the legitimacy that comes from Senate confirmation and a credible claim of speaking for the administration.

That’s particularly true for the largest problems facing the nation — from pandemics to emergency response to national security threats. Responding to large-scale issues involves numerous agencies, complicated cooperation, and high-level attention and authority. The administration’s team must be in place to get agencies to successfully cooperate and prepare for large-scale crises.

Going without appointed officials can literally be a disaster

Consider the inadequate response to Hurricane Katrina. In research I conducted on the Federal Emergency Management Agency, I found that turnover in appointed positions made it harder for FEMA to get other stakeholders to cooperate. Career FEMA employees, along with state and local officials, stopped and started while they waited for appointees in key positions managing federal relations, grants, and policy. That slowed progress on the National Response Plan, which delineates different local, state, and federal responsibilities in the event of a catastrophic hurricane. As a result, when Katrina ripped through the Gulf Coast in 2005, local, state, and federal officials were unprepared and uncoordinated in response.

Now there’s a new vacancy at the top of Homeland Security, another agency that the nation relies on for safety.

Trump has alternately blamed Democrats for delay or suggested that he simply does not want to fill many of the vacant positions. But as I’ve explained here before, leaving positions vacant is bad for the president and the country.

David E. Lewis is William R. Kenan, Jr. Professor in the Department of Political Science at Vanderbilt University and author of “The Politics of Presidential Appointments” (Princeton 2008). He can be reached at david.e.lewis@vanderbilt.edu.