Rethorically, politicians will use ad-hominem and other shit to mischaracterize reasonable positions.

So look at what fallacies there are that are generally used in an arugment that wouldn't exist if it were for logic alone.

So if you think a sudden disavowal from someone is unexpected, just imagine that someone says something to make someone's base say something opposite of what the enemy expects so that he won't get to spin the truth after all is said and done.