•Most major AI chatbots demonstrate a left-leaning bias on political questions, including those marketed as conservative.
•OpenAI's GPT-5.5 showed 80% left-leaning answers, while Deepseek's V4 Pro had 70%.
•xAI's Grok 4.3 produced more right-leaning answers than others but still had a majority of left-leaning responses.
•Google's Gemini 3.1 Pro was the most balanced, presenting both sides 93% of the time.
•The bias may stem from training data overlaps and some deliberate interventions on specific topics, like trans rights.
•The investigation highlights the difficulty of categorizing AI responses simply as left or right due to conflicts with scientific consensus or human rights.
•Full analysis and code are available on GitHub for transparency and further study.