Specifically HOW is it "messed up"?

Your Bolshevik party has made a cottage industry of implying intolerable outrages, without ever getting into specifics of what wrong was actually done.

Clearly this Berman lawyer of the Southern District of New York (SDNY) is a partisan Democrat who vitriolically opposes the president, and has weaponized the SDNY against Trump at every turn. Berman has been given free reign for 4 years, and despite his ability to use SDNY to bring charges for all that time, has been unsuccessful in doing so.

As G-man said, Obama (far more so than Trump) replaced many U.S. attorneys with guys who, like A G Eric Holder, were his partisan "wingmen" for Obama.
Obama did the same in the State Department, where Obama after his election forced the resignation of every U.S. ambassador so he could replace them with ambassadors loyal to Obama.
And as has been aabundantly visible, Obama further politicized the FBI, DOJ, CIA and other intelligence branches. Precisely what Michael Flynn was appointed National Security Advisor in 2016 to correct. Which is why he was maliciously targeted by these intelligence branches for indictment with false charges, malicious prosecution and imprisonment.

Further, Obama expanded the National Security Council to over twice its previous size, and filled it with Obama/DNC-loyalist moles and leakers to undermine the incoming Trump administration for several years, until new National Security Advisor O'Brien drained the swamp and got rid of these people, over a hundred of them, who were openly hostile to and undermining the president they were supposed to be serving. Your side complained about that as well. And the two Vindman brothers, while transferred out of the NSC, still serve in high-level Pentagon positions, despite their open hostility toward President Trump and openly undermining him. Ohh, what an outrage, that Trump would transfer them out of the NSC !