And one leading Democratic presidential candidate, Elizabeth Warren, just days ago unveiled a plan that, among other things, describes how she would move quickly to staff the government if she wins the White House.

In the plan, Warren voices the fears of many Democrats. “This will be no ordinary transition between administrations,” she states. “Unlike previous transitions, we will not be able to assume good faith cooperation on the part of the outgoing administration.”

That Democrats are making transition-related moves more than nine months before Election Day underscores not only their distrust of Trump but also the reality that taking over the U.S. government is a mammoth task with high stakes.

Any government is especially vulnerable during a transition of power, and Democrats who deal with national security are among those most concerned about a Trump-to-Democrat handover.

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Every transition is tricky given the thousands of positions that need to be filled and the array of policy priorities a new team wants to pursue.

But several Democrats attached to different 2020 campaigns mentioned very specific concerns about what a Trump departure could mean. All spoke on condition of anonymity because of the sensitivity of the issue, and because no campaign wants to be seen as assuming that Trump will lose.

The Democrats said they worry that Trump’s political appointees won’t meet with the incoming team, that there will be little, if any, paperwork left behind to guide them, and that what documents are shared will not be trustworthy.

Some fear that Trump aides will destroy paper trails related to controversial issues, not to mention quietly push through last-minute initiatives that could constrict the next administration’s ability to tackle hot button issues such as immigration or relations with Iran.

Some Democrats fear they will have to devote precious time in the early weeks of a new administration piecing together what happened under Trump on a range of areas.

And that’s all if Trump accepts the election results and agrees to leave.

“This could be the most hostile, least professional transition in American history,” a former senior official in the Barack Obama administration said. “And the new administration will have to spend the early period – when it should be hitting the ground running – unearthing buried bodies.”

One center-left organization, National Security Action, is already coordinating more than a dozen working groups focusing on specific areas -- such as climate change, China, and defense policy – with the goal of producing transition-related information for the eventual Democratic nominee.

The organization, which is led by former top officials in the Obama administration, declined to give many details about the initiative. But its leaders say the goal isn’t to endorse particular policy positions for a future Democratic president; each candidate running now presumably already has those.

Rather, what the nominee can hope to get from the working groups is a layout of what awaits them: for instance, compilations of various regulations rolled back under Trump; paths to recommitting to international pacts that Trump has abandoned; and what options – executive order? legislation? nothing? -- a new president has to overturn other Trump moves.

The initiative is called “FP21” – as in “foreign policy in 2021.” Each working group is led by a “true expert,” a representative of National Security Action said. The idea is to be “nominee-agnostic" -- offering something useful to whoever winds up challenging Trump during the general election.

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The Trump campaign did not respond to requests for comment. A White House spokesman, however, said, “The Trump administration will meet all requirements under the law as it relates to any needed transition between administrations.”

Some observers argue that if there’s hostility during the potential transition, the Democrats are at least as much to blame as Trump and his aides. For one thing, many prominent Democrats – not just presidential candidates – have spent the past three years using social media and other means to publicly bash Trump’s every move.

That criticism fuels a bigger vicious cycle, a conservative foreign policy analyst said. Trump has often acted like the anti-Obama, reversing many of the former president’s signature actions. And now Democrats are suggesting they’ll push the pendulum the other way.

“If you are part of that administration and you get shown the door, why would you be inclined to help the next guy dismantle something that you think is important?” the analyst asked.

Other supporters of Trump say Democrats are blowing things out of proportion. For one thing, they argue, there are plenty of think tanks and career government staffers who can guide an incoming administration.

“I would say ‘Take a chill pill,’” said James Carafano, a foreign policy expert with the conservative Heritage Foundation who was involved in the 2016-2017 transition from Obama to Trump. “You can gain enormous situational awareness without having Cabinet secretaries sit down and debrief you.”

Carafano also contended that there’s no legitimate reason to think Trump’s political appointees would act in an unprofessional way.

But Democrats’ transition-related fears are driven partly by how the Trump team handled the handover of power from Obama. The chaos of that transition and Trump’s early months in office have been the subject of at least one book and in-depth reports in POLITICO and elsewhere.

In spring 2016, Trump, the presumptive Republican nominee, had to be coaxed into setting up a transition team. New Jersey Gov. Chris Christie first led that team, even though Trump described having it as “bad karma,” according to an account by Christie.

But after Trump’s shocking win that November, Christie was pushed out of the top spot on the transition team amid a feud with Trump’s son-in-law Jared Kushner, to be replaced by then Vice President-elect Mike Pence.

Much of the Christie-led team’s work – which included identifying potential nominees for key government jobs – was junked as Pence and others, including Kushner, took a fresh look.

In the run up to Trump’s inauguration, according to numerous officials who have spoken to POLITICO, representatives of the president-elect were unusually slow to arrive at various agencies to meet with counterparts.

Those who did arrive expressed suspicion toward the departing political appointees, as well as the career government staffers who had served in multiple administrations. The Trump appointees spoke of the career staffers as a “deep state” determined to thwart Trump’s agenda.

Briefing books Obama aides had prepared for their successors gathered dust. Some nominees for top positions -— such as Rex Tillerson, the man Trump named as his first secretary of State -— barely interacted with the people they were replacing.

The handoff proved deeply unsettling for Obama political appointees, as well as career staffers at the National Security Council and elsewhere.

They noted that the outgoing Democratic administration was already laying the groundwork for the transition by early 2016. In preparing so far in advance, Obama was echoing the president he succeeded, Republican George W. Bush.

Bush got his transition plans going long before the 2008 election in part because he was scarred by the handoff he’d experienced from his predecessor, Bill Clinton.

The Clinton-Bush transition was harried because of the contested results of the 2000 election, which the Clinton team had hoped Vice President Al Gore would win. Bush, who oversaw the U.S. invasions of Afghanistan and Iraq after the Sept. 11, 2001, attacks, also knew he’d be handing off in a time of war, so he wanted to make the transition as smooth as possible.

Bush and Obama also did transition planning toward the end of their first terms — a more apt analogy for what Trump faces now. But people familiar with those efforts agree it was nowhere near the scale of what they did when they knew they were leaving office for good.

Still, former officials and experts say, a transition is a transition, even when a president is booted after just one term, and it’s best to plan for the possibility of defeat.

In an open letter posted by the Partnership for Public Service’s Center for Presidential Transition, a bipartisan group of former U.S. officials with experience in the topic point out that going through the motions is a good exercise for an incumbent even if he wins a second term.

“Effective planning is essential given the inevitable turnover, a Senate confirmation process which unfortunately is taking longer, and the fact that the fifth year of a president’s tenure typically provides a window for bipartisan policy development,” the letter states.

The stakes are high, especially for a new administration.

“If successful, a new president in short order will have to recruit 4,000 political appointees, including 1,200 who require Senate confirmation; prepare a $4.7 trillion budget; roll out and pursue a vigorous policy agenda; and learn how to manage a workforce of 2 million civilian employees and 2 million active duty and reserve troops,” the letter notes.

Trump has said nothing publicly to suggest he’s preparing for a handoff. Some Democrats wonder if Trump still views transition planning as “bad karma,” though it clearly didn’t hurt last time.

A White House official recently told POLITICO, however, that the administration is starting to think about staffing in a second term, but that no one has yet begun drawing up lists of potential hires.

By May, Trump technically won’t have a choice but to get a transition process going. Thanks to a 2016 law, the executive branch is required to set up transition-related infrastructure at the White House and agencies no later than six months before the election.

Once formally nominated, Trump’s Democratic challenger will be given access by the federal government to office space, secure computers and other support to go full-steam ahead with transition planning.

Democrats expect Trump to greenlight many last-minute regulatory changes and other initiatives to solidify his legacy in case he loses re-election. That’s not unprecedented — Obama did the same thing.

The challenge for a Democratic successor will be figuring out what happened that wasn’t made public, especially if Trump political appointees prove unhelpful and many top agency positions remain unfilled.

There are, of course, laws that govern how an outgoing administration handles the records it has created — what has to be archived, for how long it is classified, and what can be destroyed. The laws vary depending on whether they are being applied to specific White House offices or the Executive Branch agencies.

But Democrats are still worried that Trump and his aides will disregard or take advantage of any loopholes in those statutes.

“I would not be surprised if they try to destroy things they worked on, hide evidence or whatever,” the former senior Obama administration official said of Trump political appointees.

Democrats say one saving grace is the deep involvement of career government staffers in the transition process.

Those staffers are sworn to serve in a non-partisan fashion, implementing the policies of whoever is in the White House. But Trump political appointees have never trusted them, denigrating career employees as members of a “deep state.”

The relationship between Trump political appointees and career staffers frayed further as some such staffers obeyed subpoenas to testify in the House impeachment inquiry into Trump. At one point, the White House called those witnesses “radical unelected bureaucrats.”

Democrats expect they will have to reach deep down into the career ranks to get basic information about policymaking under Trump. Democrats may want to start making lists now of career staffers so they’ll know who to talk to, several people said.

Another major concern is whether the documents produced by the Trump administration, not just for a possible transition but even sooner, are reliable.

There have been many instances of the Trump administration including incorrect information in everything from press releases to internal communications.

In one case, the administration acknowledged serious flaws in a report it issued implying a link between immigrants and terrorism, but it refused to take down the report or correct it.