Political communication research has begun to conceptualize the Internet as a collection of disparate platforms whose influences are not uniform. The field has also come to recognize that citizens use digital media for many political purposes, some of which stand at odds with one another. The most prominent among these ends include the democratic norm of deliberation, which requires interaction between disagreeable parties; and the norm of communitarianism, which celebrates ingroup homogeneity and the avoidance of outgroup engagement. A third norm, liberal individualism, deprecates direct discussion altogether in favor of unbridled freedom of expression. This study examines the influence of distinct discourse architectures, or design philosophies of online discussion platforms, on how participants express different norms of democracy. Based on its underlying discourse architecture, each of three online discussion platforms was hypothesized to facilitate one of the aforementioned three democratic communication norms over the others. Specifically, Twitter hashtags focusing on salient political issues were expected to foster communitarianism, reader comments to the online editions of the Washington Post and the Seattle Times were predicted to promote liberal individualism, and a purpose-built site called the Living Voters Guide (LVG) was expected to elicit deliberation. Findings partially supported these hypotheses: the LVG and the issue hashtags largely hosted the expected normative characteristics, but the newspaper comments contained an unexpected combination of deliberative and liberal individualist indicators. Ultimately, this study demonstrates the power of discourse architecture to mold democratic conversations in both expected and unexpected ways.