David Rozado:

This report employs four complementary methodologies to assess political bias in prominent AI systems developed by various organizations. These four approaches are then synthesized into a unified ranking of AIs’ political bias. The four methods used to measure political bias in AIs are: comparing AI-generated text with the language used by Republican and Democratic members of the U.S. Congress; examining the dominant political viewpoints embedded in AI-generated policy recommendations for the U.S.; assessing sentiment in AI-generated text toward politically aligned public figures; and administering political-orientation tests to AIs.

The findings from all the methods outlined above point in a consistent direction. Most user-facing conversational AI systems today display left-leaning political preferences in the textual content that they generate, though the degree of this bias varies across different systems.

The left-leaning bias of AI systems is not inevitable. Studies have shown that relatively low-cost fine-tuning with politically skewed data can ideologically align an LLM toward left-leaning, moderate, or right-leaning political preferences.