Re: Erm
The 2020 election is "questionable" in the sense that you can ask questions of anything. It has been quite exhaustively questioned for several years now by some of the most highly motivated people you'll find anywhere, and none of this "questioning" has turned up anything that anyone remotely impartial considers grounds for suspicion.
I also like to mention at this point that Trump was the president at the time of the 2020 election. When Obama was president, and when Biden was president, Trump won, and those elections were apparently free and fair... but when Trump himself was president, i.e. head of the executive branch of the government, it was by his own account rigged and rotten. What does that say about him as president?
Also note that Trump himself appointed Krebs as a trustworthy figure. For Trump to attack him now as the opposite is essentially an admission that he, Trump, is a terrible judge of character and has absolutely zero reliable expertise, either his own or hired from elsewhere, in any relevant sphere.
As for Trump "trying to stop the invasion in Ukraine" (interesting choice of words there, most people would have said "invasion of Ukraine"), he's "trying to stop" it the same way he "stopped" the war in Afghanistan: by surrendering. Unfortunately it doesn't seem to have dawned on him that since it's not the US army that's actually fighting this war, he doesn't get to give that order.
"Weaponisation of the state vs Trump" - neither Biden nor Obama attempted any such thing. Biden let the law take its course in prosecuting violent criminals. Obama let federal agencies make their own operational decisions, with the result that the FBI director torpedoed Clinton's campaign. Trump is the one who is politicising and abusing those powers.