They think that if it has a (D) before or after it, it most be opposed--as vehemently as possible. With money for propaganda, shouting on their media, and relentless assaults on truth and sanity by their politicians and owned journalists, they not only choose to watch Fox and listen to National Hate Radio, they choose to actually BELIEVE what they hear.
The trouble is that many things that people with a (D) before or after their name advocate are not only good for America, they are good for the very constituencies these Republicans represent. They are often bad, sometimes very bad, for our adversaries. They don't care. If the person ordering the firing squad to shoot them is a Republican, that is preferable over the person trying to tell the shooters to stand down if that person is a Democrat. "He's a Democrat! Don't listen to him! SHOOT me!"
Therefore, stimulus packages that would benefit people in depressed economic areas--even Republican depressed economic areas--are dissed by Republican politicians, who twist themselves and their "logic" into worse contortions than a collapsed strand of overcooked spaghetti trying to explain why good is bad. Conversely, their propagandists make an effort that would rival Göbbels in the spring of 1945, trying to tell the German people how well the war was going for Germany. They try to explain why an underdog, patriotic Ukrainian president is less worthy of support than a Russian imperialist, unreformed communist secret policeman who is both a militarist and a sadist.
Is it just because Biden stands up to Putin, and Trump wouldn't? Well, YES. Just because of that. Biden is a Democrat. If Biden were to offer them pollution-free prosperity for life, and Trump would offer them bankruptcy, homelessness and uninsured ill health for life, they would choose Trump's offer, because it didn't come from a Democrat.
Is the right wing media to blame for this? Obviously. But so are its followers, who choose to believe that Jack's beanstalk really DID extend to the sky, rather than accept that no, it didn't, and there is no goose that lays golden eggs. We can discuss the how, the why, and what to do about it for the rest of our lives, but we had better accept that this is the way things are NOW, and respond accordingly.