A fair amount of ink has been spilt over the shift in Republican opinions of Vladimir Putin. Some take this as a sign of the strength of the power of elite cues driving popular opinion, whereas others see it as nothing more than run-of-the-mill political hypocrisy. There is another possibility implied by International Relations theory.
As many International Relations theorists and Pres. Obama alike have noted that Russia is weaker than the U.S. by a lot. Structural theory implies that, since Russia is much lower on the geo-political threat scale, and it is not a rising state regardless, that the U.S. should not expend a lot of material balancing against Russia. However, if the U.S. is to behave consistently as structuralists predict, and foreign policy is affected by elections and popular domestic opinions, geo-political power relationships should be reflected in electoral outcomes and popular opinion.
In other words, the change in popular opinion among partisan groups is predicted by structural int’l relations theory. Not that long ago, when Democrats were in power, they were supportive of a better relationship with Russia. Republicans at the time could be, and were, quite critical of that relationship change, but at the time they were powerless to change foreign policy. Now that Republicans are going to be responsible, they have changed their position so that their policy preferences more closely align with the relative lower power Russia has, exactly as international structural constraints would predict. (The “term of art” for this kind of effect is “second image reversed.”)
None of this is to say that some Republicans are not also being duped by a KGB thug, as more than one mechanism can operate at once. Going forward, it will be important to observe whether or not similar changes in foreign policy attitudes occur in other areas. Will Trumps foreign policy team soften their stance in other areas, such as trade? If oil prices recover, and Russia is able to increase its relative power, will Republican attitudes shift again? Importantly, there are no theoretical explanations of why or how popular opinion would shift, even though it is weakly implied by the theory when observed through the constraints of the structure. Dare I say this would be an interesting thesis?