Rigid political partisanship is STUPID when it isn't based on fact. Why can't truth be the basis of an ideology? What's wrong with that?

Republicans are well-known for rejecting/refuting what they themselves created once Democrats embrace it.  The AHCA was basically what Mitt Romney did for his state. It worked just swell! For Republicans like Mitch McConnell partisanship means always being on the exact opposite side of an issue that Democrats are on no matter how dumb they look doing it. They sluff it off. Truth is not what matters. They think no one notices what they are doing. EVERYONE notices what they are doing. Why do you think Republicans are ridiculed?  For doing exactly that. Coming up with something workable and then badmouthing it when Democrats agree and embrace it. Being opposed to everything the opposition accepts is where  it's at for Republicans. Whose very dumb idea was that? It  was not always that way. Who was the smarta** who changed things to make them unworkable?. Can anyone explain that to me logically without attacking/insulting me for daring to ask the  question?