Attested instances of persuasive discourse were examined from the perspective of conceptual blending theory to reveal that serious argumentative points are often made via the construction of unrealistic blended cognitive models. The unrealistic character of these models is often related to compression, a process by which complex relationships are reconstrued with simpler, more familiar concepts. These examples show how speakers’ compressions enable them to strategically frame controversial issues, and to evoke particular sorts of affective responses consistent with their argumentative goals. Analysis points to various constraints on blending. Besides the constitutive and governing principles outlined by Fauconnier & Turner (2002), conceptual integration operations are greatly constrained by the frames and cultural models of a particular community, together with overall knowledge of the communicative event, the cognitive task, the issues dealt with, and the discursive goal. The paper focuses on pre-natal and post-mortem blends in “pro-life” rhetoric and judicial argumentation.