Liberals experience more distress than conservatives. Why? We offer a novel explanation, the social support hypothesis. Maintaining social support and avoiding exclusion are basic human motivations, but people differ in their sensitivity to the threat of social exclusion. Among people high in the personality trait neuroticism, exclusion easily triggers feelings of vulnerability and neediness. The social support hypothesis translates this to politics. Concerned with their own vulnerability, we find that neurotic people prefer policies of care – social welfare and redistribution – but not other left-wing policies. Specifically, it is anxiety – the facet of neuroticism tapping sensitivity to social threats – that drives this link. And it is only for people experiencing exclusion that anxiety predicts support for social welfare. Our results come from two experiments and four representative surveys across two continents. They help to resolve the puzzle of liberal distress while providing a new template for research on personality and politics.