The Committee Democrats met briefly Monday afternoon to discuss how to proceed. Senator Jon Tester of Montana, the panel's top Democrat, leads the investigation.
Mr. Tester met with Sen. Johnny Isakson of Georgia, chairman of the committee, on Tuesday morning shortly after announcing the postponement.
The White House defended Dr. Jackson's report in a statement, but did not address the nature of the lawsuits against him.  "Admiral Jackson has been at the forefront of mortal combat and has saved the lives of many others in the service of this country, he has been a doctor of three presidents, Republican and Democrat, and has been praised by all of them", said Hogan Gidley, a White House press undersecretary. "Admiral Jackson's strong and decisive leadership record is exactly what is needed at V.A. to ensure that our veterans receive the benefits they deserve."
Lawmakers were already preparing to pressure Dr. Jackson on his opinion on the role of private medical care for veterans, rather than on the government-administered health care system. The senators planned to challenge their lack of administrative experience in managing a large organization. The department is the second largest in the federal government, employs more than 370,000 people and has health systems and benefits for veterans.
Prior to his nomination, Dr. Jackson had attracted little public attention and his policy views were unknown. He took a strange turn in the spotlight in January, when he appeared on national television to announce the results of Mr. Trump's first physical examination while in office. At that time, there was speculation about the president's physical and mental health, and Dr. Jackson offered effusive praise to both. Mr. Trump was satisfied with the performance.
"I have not found any reason to think that the president has any problems with his thought processes," said Dr. Jackson. At one point, he even joked that, given Mr. Trump's genetics, he could live up to 200 years if he had a healthier diet.
Mr. Trump dismissed his first secretary of Veterans Affairs amid deep ideological disagreements over the privatization of care in the department and extended the consequences of a scathing report by his inspector general on a trip that Shulkin had made last year to Britain and Denmark. Mr. Shulkin, a politically moderate physician and former hospital executive, was still well liked on Capitol Hill and among veterans' groups, who considered themselves a pragmatic leader who understood the department intimately.
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