The author needs a lesson in the US Constitution.
Separation of powers means the President has no constitutional authority to regulate the Legislature. He can use his bully pulpit to shame them into changing their own rules, but he has no power to unilaterally change their rules.
They wrote a law exempting themselves from the law. The President can’t fix that with a stroke of his pen. He has no constitutional authority.
Sen. Grassley was able to get an amendment passed that required Congress and staff to buy insurance on the Exchanges. Obama’s Office of Personnel Management reinterpreted the law to make the amendment meaningless. Fund is arguing for the Trump Administration to reinstate the intent of Grassley’s amendment.