To stretch an argument means to make a political argument that is slightly (but not glaringly) invalid. I add to existing research, which focuses on the analysis of facts and stark binary views of validity by introducing the concept of argument-stretching, which identifies subtle violations of the validity of arguments. Using this conceptual foundation, I outline an impression-formation theory to explain the impact of argument-stretching on public opinion. I suggest that people spontaneously form negative impressions of stretched arguments, and that they add these impressions to a cumulative tally of satisfaction with the argument. Finally, people translate the negative effect of argument-stretching on their account satisfaction into reduced support for the politician who stretched the argument and the policy justified by it. I confirm the hypothesized direct effects of argument-stretching on policy support and politician support in three experimental studies, and I also find evidence for the mediating effect of account satisfaction.