The increasing availability of microtargeted advertising and the accessibility of generative artificial intelligence (AI) tools, such as ChatGPT, have raised concerns about the potential misuse of large language models in scaling microtargeting efforts for political purposes. This study examines the effectiveness of a "manipulation machine" that uses AI to create personalized political ads based on individuals' personality traits. Four studies were conducted to assess the impact of such personalized ads. The results show that personalized political ads are more effective than nonpersonalized ones. Additionally, the study demonstrates the feasibility of automatically generating and validating these personalized ads on a large scale. These findings highlight the potential risks of using AI and microtargeting to craft political messages that resonate with individuals based on their personality traits. The study emphasizes the need for ethical scrutiny and policy-oriented solutions to govern the use of AI in shaping public opinion and safeguarding electoral integrity. The research also explores the use of generative AI to derive personalized political messages from a single template and to infer personality traits from consumed text. The study shows that AI can be used to create ads that target individuals based on their personality traits, which can be effective in persuasion. However, the study also notes the potential for misuse of this technology, including the creation of manipulative content. The study concludes that while the effect sizes are small, they can be significant at scale, and the automation of political microtargeting is crucial for achieving such scale. The study also discusses the need for transparency and user empowerment in the digital landscape to address the challenges stemming from information and power imbalances between platforms and users.The increasing availability of microtargeted advertising and the accessibility of generative artificial intelligence (AI) tools, such as ChatGPT, have raised concerns about the potential misuse of large language models in scaling microtargeting efforts for political purposes. This study examines the effectiveness of a "manipulation machine" that uses AI to create personalized political ads based on individuals' personality traits. Four studies were conducted to assess the impact of such personalized ads. The results show that personalized political ads are more effective than nonpersonalized ones. Additionally, the study demonstrates the feasibility of automatically generating and validating these personalized ads on a large scale. These findings highlight the potential risks of using AI and microtargeting to craft political messages that resonate with individuals based on their personality traits. The study emphasizes the need for ethical scrutiny and policy-oriented solutions to govern the use of AI in shaping public opinion and safeguarding electoral integrity. The research also explores the use of generative AI to derive personalized political messages from a single template and to infer personality traits from consumed text. The study shows that AI can be used to create ads that target individuals based on their personality traits, which can be effective in persuasion. However, the study also notes the potential for misuse of this technology, including the creation of manipulative content. The study concludes that while the effect sizes are small, they can be significant at scale, and the automation of political microtargeting is crucial for achieving such scale. The study also discusses the need for transparency and user empowerment in the digital landscape to address the challenges stemming from information and power imbalances between platforms and users.