President Donald Trump, more isolated than at any point in his presidency, is scheduled to leave Washington at the end of this week for a holiday respite, two-plus weeks at his Florida resort, Mar-a-Lago. When he returns in January, he will be girding for what is likely to be the most difficult year yet of his tumultuous presidency.

His approval ratings aren’t much different than they were when he took office. His hard-core supporters haven’t budged. GOP elected officials remain hesitant to break with him. But his party took a beating in the midterm elections, and the legal process continues to move closer to him. Newly empowered House Democrats are preparing to challenge his authority with hearings and investigations.

Republican elected officials have stuck with him, mindful of his support among the GOP rank and file. But Senate Republicans last week joined with Democrats to deliver a pair of rebukes over the administration’s policy toward Saudi Arabia and the president’s unwillingness to condemn Crown Prince Mohammed bin Salman, whom the CIA concluded sanctioned the murder of journalist and Washington Post contributing columnist Jamal Khashoggi. Was that a one-off or cracks in the wall?

Trump’s on-again, off-again search for a replacement for outgoing White House Chief of Staff John Kelly is symptomatic of his situation. In any presidency, the role of chief of staff is vital. For Trump, at this moment, it could be crucial. Yet potential contenders walked away from the job until the president tweeted on Friday afternoon that he was naming budget director Mick Mulvaney, but only as his acting chief of staff, and not to the permanent position.

The announcement came hours after former New Jersey Gov. Chris Christie took himself out of contention for the post. His decision to withdraw from consideration came at the end of a week that began when Nick Ayers, who serves as chief of staff to Vice President Mike Pence and who was in line to succeed Kelly, suddenly backed out. A series of names were floated, but none have come to fruition.

The decisions by Ayers, Christie and others underscores the precariousness of Trump’s position. At a time when he will need all the strength, wisdom, firepower and support directly around him, Trump presides over a White House that is thinning out rather than beefing up.

The White House Counsel’s Office is understaffed heading into a year that could bring multiple requests for documents from congressional committees and the possibility of impeachment proceedings, if what special counsel Robert Mueller ultimately reports rises to that level. So far that is an open question. Others already have moved out of the White House to jobs on the Trump 2020 campaign or the private sector. More could follow in the months ahead.

Some loyalists remain, among them the president’s daughter Ivanka and son-in-law Jared Kushner, as well as Kellyanne Conway and Sarah Sanders. But on the issue of fresh recruits, the question is who would want to come to work for a president at this moment, knowing that it could result in sizable legal fees as a side benefit?

For Trump, a group of people he once counted as among his most trusted advisers has been turned into a weapon in the hands of prosecutors. Michael Cohen, Trump’s longtime fixer and lawyer who once said he would take a bullet for Trump, has turned. Last week Cohen was sentenced to three years in prison for his crimes. He told the court that he had done some of what he did, including lying to Congress, to hide the “dirty deeds” of Trump.

Another who once protected the president and is now on the other side is David Pecker of American Media Inc. AMI is publisher of the National Enquirer, which shielded Trump through the campaign by buying and killing damaging stories and through a series of phony stories about Hillary Clinton.

Meanwhile, Trump’s former national security adviser, Michael Flynn, has pleaded guilty to lying to the FBI and has cooperated with prosecutors. His one-time campaign chairman Paul Manafort is in prison, though for crimes unrelated to the campaign. His one-time deputy campaign manager Rick Gates, Manafort’s business partner, has also pleaded guilty for his role in the Manafort business.

No one outside Mueller’s circle knows what the final conclusions of his investigation will say — on Russia, on campaign finance violations, on the financial dealings of the Trump Organization, on any of the multiple threads that now exist.

Congress is not likely to impeach the president over violations of campaign finance law, but the congressional machinery is cranking up to investigate the many aspects of Trump’s operations that have fallen under the view of prosecutors. The president can only wait, nervously, to see where it all leads.