> Three of the sources said officials at the Department of Defense had previously raised concerns about political donations made by Beck to Democrats.

If true, this is insane. I don’t understand how the US government firing an employee for personal campaign donations squares with modern interpretations of the first amendment.

It doesn't. Nothing squares with anything anymore. "Rules for thee, not for me" is the name of the game from here on out.

Once you stop treating this administration like previous ones, and start treating it like the banana republic it is, things start to make much more sense.

As the source article describes, it has nothing to do with the First Amendment. The Secretary of Defense is conducting a political purge of the Pentagon. The administration has stated repeatedly and at length that they expect personal loyalty to Donald Trump from the entire federal government, and that they have the right to remove anyone who doesn't show that loyalty or won't do what he wants.