When faced with an incumbent party that is deliberately tilting the electoral and institutional playing field, under what conditions should small-d democracy advocates respond with hardball tactics such as Court-packing? This paper surveys the comparative literature on democratic erosion for key lessons regarding the role of courts in polities where democratic erosion is underway. The literature suggests that independent courts may sometimes operate as guardrails of democracy, but that once captured by anti-system parties, courts may also serve as effective agents of democratic erosion. The paper then draws on the history of Court-packing in the United States in an effort to confirm and sharpen these lessons. The key takeaway is that we should distinguish between constitutional hardball in service of democratic erosion and constitutional hardball in service of democratic preservation or renewal. In this light, given the role played by the current Supreme Court in ongoing processes of democratic backsliding, Democratic Court-expansion, combined with institutional reform of the judicial selection process, may be the least-bad option for restoring the Court’s role as democratic guardrail.