Libs, citing game theory while failing to understand that the whole point of the classic prisoner's dilemma example is that everyone picking the unilaterally optimal strategy doesn't result in the optimal outcome. Not to mention they always frame elections as a one-time game (e.g. "This is the most important election of our lifetime!"/"We can bully the neolibs later after we elect them!") when this is clearly a repeating game where earlier iterations have lasting effects on the payoffs from later iterations. Voting Dem now tends to make both the next Dem candidate and the next Republican worse because it validates their strategy of being only slightly better than the other guy.