Trump’s empty administration: What’s behind the high number of vacant government jobs Trump has more unfilled top jobs than other recent presidents at this point.

 -- It's no secret that the Trump administration is way behind on filling key positions as hundreds of top jobs sit unfilled nearly 150 days into the president’s term.

President Trump has complained that the process of confirming his nominees is “record-setting long” and recently took to Twitter to blame the Democrats for stalling the process.

But while the Senate has taken longer to confirm Trump's nominees than it took with nominees of the previous several presidents, the real culprit may be the president’s chaotic and disorganized transition.

Transition woes

The groundwork of lining up potential nominees for a new administration usually begins well before Election Day with candidates beginning early to identify people they would want in the executive branch. But with the Trump campaign and later the Trump transition almost none of that preparation took place.

Once a potential nominee is identified, it can take upwards of 45 days for that person to go through an FBI background check and a review by the Office of Government Ethics, all of which is typically done before the nominee's name is sent to the Senate for confirmation.

Previous incoming presidents identified a large group of potential nominees either during the campaign or the transition -- and even before it was determined for which job each person would be nominated.

But the Trump transition was well behind schedule compared to other recent presidents in lining up candidates for key roles.

The delayed start continues to plague the administration nearly 150 days in, with only 151 nominations having been announced for the more than 500 critical jobs across the executive branch that require Senate confirmation.

The Obama administration had announced 284 nominations by this point, and Bush had named 245, according to figures compiled by the nonpartisan Partnership for Public Service.

It's not that others haven't been chosen. In fact, a source familiar with the process tells ABC News that most of the nominees for vacant posts have been identified but that their background checks are in process.

According to the source, President Trump has signed off on more than 350 nominees, which would mean that more than 200 of these people are currently undergoing a background review.

Clay Johnson, who was in charge of hiring for President George W. Bush in 2000 both during the transition and in the White House, remembers getting down to work planning the Bush transition and lining up candidates for key jobs more than a year before Election Day.

“I started sending names and identifying people 16 months ahead of time,” Johnson said. “The more time you have to get organized and establish relationships with the FBI and the Office of Government Ethics, and different people you consider for jobs, the more time you have, then the faster you can do your work.”

Early preparation was also the practice of subsequent GOP nominees, most notably Mitt Romney, who had a team of hundreds working on transition matters in the final days of his campaign in 2012.

“He was probably the most prepared candidate the week before the election ever in history,” Johnson said.

The Trump transition, by comparison, was riddled with inefficiencies and plagued by staff shakeups right up to, and directly after, the election.

New Jersey Gov. Chris Christie – who had been leading the transition in the weeks before the election – was fired just days after Election Day. He was replaced by then Vice President-elect Mike Pence, who saw the process through to the inauguration.

The job of filling the remaining vacancies in the new administration then fell to Johnny DeStefano, a former political director to former House Speaker John Boehner, who was hired early this year as the director of presidential personnel.

From his corner office in the Old Executive Office Building in the White House complex, DeStefano is in charge of placing people in the hundreds of positions that remain empty throughout the administration.

While this responsibility may be a challenge after a disorganized transition, the White House points to the long, behind-the-scenes process of shepherding each nominee from selection to confirmation as a key cause of the current backlog.

“Each nominee must pass a thorough background investigation before they can be officially nominated – everything from standard background checks to careful research and individual outreach to peers and colleagues," White House spokesperson Lindsay Walters says of the process. "These individuals will be tasked with turning the president’s vision into reality on a daily basis, and it’s extremely important for the White House to ensure that they are individuals of the highest caliber who will passionately implement his policies.”

What is the process?

Before a nomination can be announced, the White House and the secretary of the department with the vacant position must first agree on the desired pick. Once a nominee is decided upon, DeStefano brings the final selections to President Trump during a weekly appointment for the president's final review and approval.

Even though the president’s signature represents a significant step, it doesn’t mean the nomination is ready to be announced. Instead, the president’s signoff begins another involved process: background checks.

And it’s in this phase where many of the administration’s nominees-in-waiting currently are.

The Office of Government Ethics and the FBI complete separate checks of every selected individual.

The process represents a substantial lift for the Office of Government Ethics, which has a staff of 71 people working to help guide hundreds of nominees through the ethics process. An ethics official with knowledge of the process says OGE is working at a faster pace than ever before on the process but can only move as quickly as it receives the necessary information from each individual undergoing the checks.

"OGE can't review reports that it does not have until we receive them. Once we have received them, OGE has been moving these reports faster than we did in the 2009 transition," a spokesman for the ethics office said.

One factor that may be further complicating the background check process, an administration official suggests, is that the president has selected a high number of people with backgrounds in business and other fields outside government, which may require more review than for someone with a more traditional government career.

Johnson said that while nominees with a history in business typically have financial holdings that make their background checks more complicated, he says it doesn’t excuse the current high number of vacancies.

People with “complicated financial dealings have been asked to be considered for appointments before and ended up with appointments,” he said, noting that it isn’t necessary to name people with complicated financial holdings to all the open positions.

A former Obama administration official also pushed back against the notion that the Trump White House may face an unusual challenge due to naming a high number of people with backgrounds outside of government.

The Obama administration “certainly put an emphasis on finding a diversity of candidates that represented the diversity of the country in terms of background and experience,” the former official said.

"We had plenty of talented candidates from various financial backgrounds who were eager to work in the Obama administration. Though someone's background can make vetting a challenge, it remained a thorough process and a priority for the administration,” the official added.

Once a person's background review is done, the president can formally announce the nomination and send it to the Senate for confirmation. The Senate then completes its own vetting process before taking a final vote.

It’s at this stage where another 90 some Trump administration nominees are awaiting final approval.

Of the 151 nominees that have been announced and sent to the Senate, only 43 have been confirmed. In contrast, Obama had 151 nominees confirmed by this point, with Senate review and approval taking on average 32 days for each of them.

President Trump’s nominees are taking 43 days on average to be confirmed, about 11 days longer for each person.

In addition to the president's laying blame on Senate Democrats, Senate Majority Leader Mitch McConnell’s office recently sent out an email titled “Dems Slow-Walk Uncontroversial Nominees,” in an apparent effort to build a case that Democrats have forced undue procedural delays in the confirmation process.

But Democrats say the problem is the low number of nominees sent to the Senate for confirmation.

"It’s hard to hold up a nomination that hasn’t been made, particularly when I am not aware – I certainly have not been contacted by the administration giving me a list to get back to them with my advice," Maryland Sen. Ben Carden said recently. Before a nomination can be announced, the White House and the secretary of the department with the vacant position must first agree on the desired pick.

ABC's Katherine Faulders and Alex Mallin contributed reporting.