Donald Trump has long wanted to be able to fire any civil servant he deems insufficiently loyal to him. The problem has always been the Pendleton Act, which establishes a complicated process for firing civil servants, and then only for malfeasance. For Trump, when a civil servant refuses to carry out his (illegal) order, that is malfeasance. Unfortunately for him, the courts tend not to see refusal to carry out an illegal order as grounds for dismissal.
On the other hand, political appointees serve at the pleasure of the president and can be fired for any reason or no reason (except being a member of a protected class, so being Black is not grounds for being fired but being a redhead could be). At the end of 2020, Trump created something called "Schedule F," which listed civil service employees who had some policy-making authority. He claimed these people were exempt from civil service protections and could be fired at will by the president. The list included 50,000 positions. Just imagine what would happen if 50,000 people all started making policy decisions. Schedule F was short lived because Joe Biden canceled it immediately upon taking office in Jan. 2021.
Now Trump is back at work. This time he signed an XO creating "Schedule G," a new class of federal workers the president can hire and fire at will. These are not career workers and their jobs end when the president who appointed them leaves office. Trump believes that having short term workers with no future prospects in their job will motivate them to work harder and be more efficient. That is arguable, but it will undoubtedly motivate them to obey his orders. The largest federal employee union, the Amercian Federation of Government Employees. is deeply concerned about this. Maybe they contacted Sen. Susan Collins (R-ME). They didn't say. There will likely be legal challenges to the new schedule. (V)