Updated

The exit of Tom Price as the U.S. health secretary has many wondering if Republicans will be able to deliver on their promise to repeal and replace ObamaCare.

The Republican Party as of late has struggled to advance its health care agenda even though they have control of the White House and both chambers of Congress.

Price’s exit on Friday amid investigations into his use of costly charter flights for official travel at taxpayer expense seems to be the latest self-inflicted blow.

Regaining momentum to replace former President Obama's law will be more difficult now that Trump administration must now also find his replacement.

“I think health care is a dead letter through the next election,” said Joe Antos, a policy expert with the business-oriented American Enterprise Institute.

Price — who Trump concluded had become a distraction — had been on the rocks with the president since before the travel flap. A former Republican congressman from Georgia, he proved less helpful than expected on the health care fight. Price played a supporting role while Vice President Mike Pence took the lead, especially with the Senate.

The health secretary's departure — the latest in a list that now includes Trump's chief of staff, national security adviser, press secretary and two communications directors — is also unlikely to end what has been a steady drip of revelations about potentially inappropriate travel on the part of Cabinet members.

Treasury Secretary Steven Mnuchin has come under fire for requesting a government aircraft to use on his honeymoon, while Interior Secretary Ryan Zinke said he'd taken three charter flights while in office, including a $12,375 late-night trip from Las Vegas to his home state of Montana in June. The Environmental Protection Agency's inspector general has opened an inquiry into Administrator Scott Pruitt's frequent taxpayer-funded travel on commercial planes.

The House Oversight and Government Reform committee has launched a government-wide investigation of top political appointees' travel.

Trump ran on a pledge to "drain the swamp" in Washington and has taken pride in his efforts to reduce federal spending and negotiate better deals on behalf of American taxpayers.

In a memo Friday, White House budget director Mick Mulvaney said all travel on government-owned, rented, leased or chartered aircraft will now have to be approved by the president's chief of staff, John Kelly. That gives more oversight power to a man who has tried to impose order and structure on what has been a chaotic White House.

On health care, the task of installing another secretary at the Health and Human Services department won't be easy.

The nominee will have to run the gauntlet of Senate confirmation. The already contentious process will be more challenging as Democrats shift from playing defense to offense on health care, heartened by the survival of the Affordable Care Act and polls showing support for the government's leading role in health care.

And HHS is not the only department that needs a leader. Trump has yet to pick a permanent replacement for Kelly, who left his previous job running the Department of Homeland Security in July.

Two potential candidates for health secretary already hold senior Senate-confirmed posts at HHS, which could be a plus for the White House.

Seema Verma leads the Centers for Medicare and Medicaid Services, which runs major insurance programs. Scott Gottlieb heads the Food and Drug Administration, which has regulatory authority across pharmaceuticals and consumer products.

Verma is a protege of Pence, who played a major role in negotiations with Congress this year on the futile "Obamacare" repeal effort.

Verma is seen as a talented policy expert, but she's still relatively new to the ways of Washington. Gottlieb is a veteran, but he may prefer the FDA and its clearly defined mission to the quicksand of health care policy.

Also mentioned is Louisiana GOP Sen. Bill Cassidy, co-author of the last Republican health care bill that failed to advance. Cassidy would probably win confirmation easily, but his prospects in the Senate appear bright, and he may not want to depart for a Cabinet post in a tumultuous administration.

Another potential candidate is Florida's Republican Gov. Rick Scott, a former hospital executive who is term-limited after 2018. But Scott is expected to mount a Senate campaign against Democratic incumbent Sen. Bill Nelson next year, and he may have ambitions and interests beyond health care.

The Associated Press contributed to this report.