WASHINGTON – On a day he will try — again — to reset his embattled presidency, Donald Trump kicked off Monday by again threatening lawmakers' health insurance.

The president repeated his threat — initially made on Saturday — to strip the employer contribution for health insurance away from members of Congress in a morning tweet fired off about an hour before he swore in his new White House chief of staff, retired Marine Corps Gen. John Kelly.

Trump tweeted that the Affordable Care Act is "hurting people," and insurance companies and lawmakers should share in that pain. On Congress members, he asked, "why should Congress not be paying what public pays?"

"If ObamaCare is hurting people, & it is, why shouldn't it hurt the insurance companies & why should Congress not be paying what public pays?" he tweeted.

As part of the 2010 health care law, members of Congress and many staffers were shifted out of the usual Federal Employees Health Benefits structure and into the new insurance exchanges set up by the law.

The Office of Personnel Management under President Barack Obama determined that the employer contribution portion of the premiums could flow through the District of Columbia's health insurance exchange.

Trump has the authority to end lawmakers' exemption, as several conservative political groups are urging him to do.

The first part of Trump's tweet appeared to be another threat to stop making cost sharing reduction payments to insurance companies under the 2010 health care law that help subsidize expenses for lower-income policyholders. Some Democrats and experts, however, warn that would amount to the president purposely hurting regular people in an attempt to force Democrats to cut a deal on health care.