Your history is not accurate. Dems have pretty much ignored Ukraine since 2014. Obama sent blankets and deferred to Merkel then. Did Dems cheer when Trump sent missiles to Ukraine? Nope. Biden ignored Ukraine in 2021 while partnering with Putin to nuke up Iran. Putin took that disinterest as a green light. Until Putin fully invaded Dems have only been interested in Ukraine to hammer on Trump. The idea that the Dems are using Ukraine as some kind of base is just fanciful.
The Dems have been using Ukraine as “some kind of money pit” ever since the Biden Crime Family got into it during the Obama administration. This even intensified as the 2016 elections approached, and some of it continued even after Trump had been elected. Many of these Ukies were players in the “Russia Russia Russia” hoax - take the Vindmans, for example.
I think Trump was completely unaware, at least in part because he didn’t have a lot of foreign experience and the Dems had all their players in place. Pompeo was good but a lot of the Ukie changes were a done deal by the time he got there.
Putin is just Putin, which can be good or bad. I was in Russia about 5 years ago and had an interesting conversation with a Russian who said that we didn’t realize that after the collapse of the Soviet Union, Russia went from state-sanctioned abuse of law, sort of like ours, where an out of control state can have midnight raids, terrorize the population, ignore favored criminals and do whatever it wants, to general chaos, gang rule, street crime and poverty. Putin brought them out of all this, and Russians have always loved a strong man (sort of like Trump).
Putin had been KGB and knew where the bodies were buried, who to go after and how the game was played. And the reason he was popular is that he made Russia a functional, enterprising state basically governed by the rule of law, or certainly a lot more than it had been prior to him.