The speculation that Trump is a stooge for Putin is not sound at all, to put it politely. Trump is president of the most powerful country on the planet, connected to the wealthiest and most powerful people on the planet. And he's taking payolla from a second rate power to go against American interests?
Aside from economic interests, if the National Security appartus or intelligence agencies got even a sniff of that he would be dead. They monitor their leaders constantly to make sure.
Having said that, U.S. and Europe courted Ukraine into working them into the E.U. and eventually into NATO, U.S. made this inention explicit. This is what precipitated the invasion. Within the first week or so of the war, Zelensky and Putin had a deal worked in principle and Boris went to Ukraine to "talk" him out of it. Now that the war is unwinnable, Trump is making Zelensky look like the bad guy and throwing him under the bus to save face for the U.S.