A new study comparing major AI chatbots found significant differences in how they handle political questions, with ChatGPT showing a strong leftward tilt while Google's Gemini emerged as the most balanced option. Researchers at Dartmouth College and Stanford University tested OpenAI's ChatGPT, Google's Gemini, Anthropic's Claude, Elon Musk's Grok, China's DeepSeek, and Gab's conservative-focused Arya using political questions designed to reveal ideological patterns.

Which AI Chatbots Show the Most Political Bias?

The findings paint a stark picture of how different AI models respond to contentious political issues. ChatGPT showed the strongest leftward lean, with 80% of its responses presenting only left-leaning arguments, while just 3% offered exclusively right-leaning positions. The remaining responses included perspectives from both sides of political debates. In contrast, Google's Gemini delivered balanced responses in 93% of cases, making it the most likely model to present competing arguments on controversial issues.

The study used more than two dozen political prompts originally developed in a 2025 study by Dartmouth's Polarization Research Lab and Stanford researchers. These questions covered topics ranging from campaign finance and affirmative action to military intervention and healthcare policy. One example asked whether the U.S. Supreme Court should overturn the landmark 2010 Citizens United decision, which expanded corporate political spending rights. ChatGPT argued that unlimited corporate spending gives wealthy groups excessive influence over elections, while Gemini and Claude presented arguments both supporting and opposing the ruling.

The study also found that ChatGPT frequently supported positions such as abolishing the Electoral College, increasing taxes on wealthy Americans, adopting single-payer healthcare, and opposing the death penalty. These findings come amid heightened scrutiny from President Donald Trump and conservative allies, who have accused AI companies of embedding liberal biases into their products.

How Do AI Companies Respond to Bias Accusations?

AI companies dispute claims that their systems intentionally favor one ideology. Google spokesperson Lauren Fine told the Washington Post that Gemini is specifically designed to provide balanced responses without promoting a political agenda. Anthropic spokesperson Michael Aciman similarly said Claude is trained to treat political viewpoints equally and undergoes extensive bias testing before release.

OpenAI, DeepSeek, xAI, and Gab did not respond to requests for comment, according to the report. The silence from xAI, which operates Grok, is notable given that Elon Musk has positioned his company as an alternative to what he views as politically biased AI systems.

Experts caution, however, that true political neutrality may be impossible to achieve. Ceren Budak, who studies technology and political polarization at the University of Michigan, told the Washington Post that even a "both sides" approach reflects value judgments about how information should be presented. This raises a fundamental question about whether neutrality is a realistic goal or whether all AI systems inevitably embed choices about what counts as balanced.

What Do Users Actually Prefer in AI Responses?

Interestingly, the study found that Americans generally prefer balanced AI responses. In a companion survey involving 10,000 participants, researchers found users favored answers that explained multiple viewpoints, even when those perspectives did not align with their own political beliefs. This suggests that users value comprehensiveness and fairness over confirmation of their existing views.

"This is important because these AI tools are becoming increasingly influential in how people understand political issues," said Sean Westwood, director of Dartmouth's Polarization Research Lab. He argued that chatbots often do not present "a truly neutral representation" of complex policy debates.

Sean Westwood, Director of Polarization Research Lab at Dartmouth College

Steps to Evaluate AI Bias in Your Own Interactions

• Test Multiple Models: Ask the same political question to different AI chatbots and compare how they frame arguments. Notice whether one model presents only one side or consistently includes counterarguments.
• Look for Argument Completeness: Check whether the AI acknowledges legitimate points from opposing viewpoints or dismisses them without serious engagement. Balanced responses should explain why reasonable people disagree.
• Examine Source Material: When an AI cites studies or statistics to support a political position, verify those claims independently. Bias often appears in selective citation rather than outright falsehoods.
• Consider Your Own Preferences: Reflect on whether you're drawn to AI responses that confirm your existing beliefs. The study found users prefer balanced information, but confirmation bias can still influence which tools we trust.

The timing of this study reflects broader political pressure on AI companies. Earlier this year, Trump signed an executive order calling for AI systems used by the federal government to function as "neutral, nonpartisan tools," prompting concerns among some Democrats that political pressure could push AI development in the opposite direction. This creates a difficult situation for AI companies caught between competing demands for neutrality and accusations of bias from both sides of the political spectrum.

The research underscores that as AI chatbots become increasingly influential sources of information for millions of users, questions about their political leanings are no longer academic. Whether intentional or not, the differences in how these models present political arguments can shape how people understand contested issues. The fact that users prefer balanced responses suggests there is market demand for more neutral AI systems, even if perfect neutrality remains philosophically elusive.