WASHINGTON — After weeks of uncertainty atop the Department of Veterans Affairs, United States President Donald Trump dismissed its secretary David Shulkin on Wednesday (March 29) and announced he would replace him with the White House physician, Dr Ronny Jackson, a rear admiral in the Navy.

If confirmed, Dr Jackson, a career naval officer who has no real experience running a large bureaucracy, would inherit a set of challenges that have bedeviled Democratic and Republican administrations alike.

The department, the federal government’s second largest, has been burdened for years by aging infrastructure, an inefficient health care system and an unwieldy 360,000-person workforce.

He could also quickly face crucial, multibillion-dollar decisions over the replacement of its outdated computerised records system and legislation that would ease the rules around veterans seeking private health care at government expense.

The announcement punctuated what has been a rapid fall from favour for Mr Shulkin, a politically moderate former hospital executive who delivered Mr Trump a string of bipartisan legislative victories at a time when he was struggling to find them.

But in his final weeks, he struggled to fight off attempts by more conservative administration officials to have him removed and was dogged by an unflattering inspector general report on his overseas travel that undermined his relationship with the president.

Mr Shulkin’s departure was the latest chapter in the remaking of Mr Trump’s team of senior advisers, a shake-up that has led to the replacement of the secretary of state, the director of the CIA and the national security adviser, along with White House aides.

In the midst of that turmoil, Dr Jackson, 50, who was named to his current position by President Barack Obama in 2013, has grown close with Mr Trump, a commander in chief who enjoys familiar faces in his orbit and often rewards them with new roles.

Dr Jackson had a rare turn in the spotlight in January, when he announced the results of Mr Trump’s physical, his first while in office, and addressed speculation over the president’s physical and mental health.

Revealing the results of the president’s examination by a team of specialists, Dr Jackson declared Mr Trump to be in “excellent health” and said he had passed a cognitive screening.

“I’ve found no reason whatsoever to think the president has any issues whatsoever with his thought processes,” Dr Jackson said.

In a Twitter post on Wednesday announcing the changes, Mr Trump called Dr Jackson “highly respected” and thanked Mr Shulkin for “service to our country and to our great veterans.”

Mr Trump said that Mr Robert Wilkie, the undersecretary for defence personnel and readiness at the Defence Department, would serve as acting secretary in the meantime, bypassing the department’s deputy secretary, Mr Thomas Bowman.

The White House did not respond to a request asking who would replace Dr Jackson.

Mr Shulkin, who served as undersecretary of the VA in the Obama administration, had begun to make headway on some of the department’s most persistent problems, helping guide into law measures meant to improve services for more than 20 million veterans.

Those included an expansion of the GI Bill for post-9/11 veterans, legislation that makes it easier for the department to remove bad employees and a law that streamlines the appeals process for veterans seeking disability benefits.

Those successes and his easy grasp of complicated policy issues won Mr Shulkin deep support on Capitol Hill and among veterans groups, who hold considerable sway in Washington.

And Mr Trump, who made veterans issues and overhauling the scandal-ridden department a focal point of his campaign, showered Mr Shulkin with praise. At a bill-signing ceremony in June, the president teased that the secretary need never worry about hearing his “Apprentice”-era catchphrase, “You’re fired.”

“We’ll never have to use those words on our David,” Mr Trump said.

But in recent months, a group of conservative Trump administration appointees at the White House and the department began to break with the secretary and plot his ouster. At issue was how far and how fast to privatise health care for veterans, a long-sought goal for conservatives like the Koch brothers.

The officials — who included Mr Shulkin’s press secretary and assistant secretary for communications, along with a top White House domestic policy aide — came to consider Mr Shulkin and his top deputy as obstacles.

The secretary’s troubles only grew when what had been an internal power struggle burst into the open in February, after the department’s inspector general issued a scathing report on a trip Mr Shulkin took last year to Britain and Denmark. The report, describing what it called “serious derelictions,” found the secretary had spent much of the trip sightseeing and had improperly accepted Wimbledon tickets as a gift.

Critics of the secretary seized on the report to try to hasten his removal.

Mr Shulkin, fearing a coup, went public with a warning about officials “trying to undermine the department from within” and cut off those he saw as disloyal. The efforts backfired.

At the White House, senior officials came to believe that Mr Shulkin had misled them about the contents of the report. And the secretary’s public declarations only further aggravated top officials, who felt Mr Shulkin had gone too far in commenting on internal politics with news outlets and had opened the administration to sharp criticism over his trip to Europe, which the report said cost more than US$122,000 (S$159,974).

But as recently as early March, after meetings with Mr John Kelly, the White House chief of staff, Mr Shulkin publicly claimed victory, signaling that he had the White House’s support to remove officials opposing him. The victory was short-lived.

Despite his problems with the White House, Mr Shulkin remained overwhelmingly popular on Capitol Hill, where the Senate unanimously confirmed him last year, and among the veterans groups that have traditionally held outsize influence in Washington.

In recent weeks, leaders from both parties publicly and privately signaled their support, even as rumous of his replacement appeared in news reports.

But Mr Trump had had enough.

He began to discuss successors in recent weeks, even considering Energy Secretary Rick Perry as a possibility. He told friends last weekend that he would fire Mr Shulkin, it was just a question of when.

Mr Trump kept his interest in choosing Dr Jackson relatively quiet, telling only a small number of people this week.

A Navy doctor since 1995, Dr Jackson deployed as an emergency medicine physician to Taqaddum, Iraq, during the Iraq War. He has served as a member of the White House medical unit since 2006 and as its lead physician since 2013, overseeing Obama’s physicals.

Dr Jackson had told several people that he planned to retire from Washington after Mr Obama left office. But Mr Trump, whose previous personal physician made headlines with a series of unauthorised news interviews about his patient, asked Dr Jackson to stay on.

His policy views, though, are far less known, especially on Capitol Hill, where the Senate will decide whether he is up to leading the department.

Democrats, moderate Republicans and mainline veterans groups have all feared that Mr Shulkin’s departure could clear the way for a more aggressive push for government-subsidized private care at the department.

“Every major veterans organisation in this country vigorously opposes the privatisation of the VA,” Senator Bernie Sanders, a member of the Senate Veterans Affairs Committee, said in a statement. “I stand with them. Our job is to strengthen the VA in order to provide high-quality care to our veterans, not dismember it.”

Representative Phil Roe, chairman of the House Veterans Affairs Committee, said Wednesday that he considered Mr Shulkin a friend and regretted his departure.

“I respect President Trump’s decision, support the president’s agenda and remain willing to work with anyone committed to doing the right thing on behalf of our nation’s veterans,” Mr Roe said. THE NEW YORK TIMES