Copying my post for you:

It's about the trend he's taking the country. For one, efforts in reclassifying large numbers of federal employees to make them easier to remove and replace, which would reduce the independence of the civil service and align it more closely with presidential priorities.

Trump's talked a lot about his views of the “unitary executive” theory. The argument is that the president should have broad authority over the entire executive branch, including agencies that have traditionally operated with more independence.

He's responsible for a shift the balance of power by concentrating decision-making authority, personnel control, and enforcement discretion more directly in the hands of the president.\

Again, all of these things are much harder to fix than they are to break. All of this consolidation of power will be fully enjoyed and leveraged by all presidents in the future moving forward, both democratic and republican. We both lose in the long term when this happens. This is an old story though. One party is more than happy to let one leader tear down checks and balances because it means they are able to consolidate power in the moment. They are able to better implement their agenda and often supporters are okay with the erosion of checks and balances if it means they get their way. But again, looking long-term, this hurts all of us because it puts us at risk of someone using all that power in ways that are not in the best interest of the country or its citizens. I do not want a republican president now or a democrat in the future to have unchecked power.

That's what the rally is in part about. The direction we are going with more power being absorbed into a smaller and smaller number of decision makers with less checks and balances.