Balanced state admissions locked in the antebellum slavery status quo.

Evidence

With the Senate evenly divided, neither North nor South could dominate admissions politics, but each side could ensure the continuation of the status quo. The result was a series of political compromises in which slave and free states were admitted in pairs. Thus, at the time of the debate over the admission of Missouri as a slave state in 1819, there were eleven northern states and eleven southern states in the Union. Missouri’s admission, therefore, created the possibility that slave states would predominate over free ones. To prevent this political shift and the policy consequences it would threaten, Northerners in Congress insisted that Maine enter the Union as a free state as a concession for their allowing Missouri to enter as a slave state. The Missouri Compromise established a pattern that Congress would follow for some time, with slave and free states entering together, to preserve the Senate’s sectional balance. This so-called balance rule “protected Northerners against the dominance of national policymaking by the South, and it protected Southerners against the antislavery initiatives of the North.” In other words, it enabled Congress—in a bipartisan and bisectional manner—to lock in the national status quo on the slavery question. — Daryl Levinson and Benjamin I. Sachs, Political Entrenchment and Public Law, 295

Categorization

• ADDENDUM: Relevant to the article on sacrifice as stabilizer — here a nominally neutral admissions rule functions as a status-quo stabilizer of a deeply unjust institution, echoing how ritual stabilized stratified societies.
• XREF: Parallels the idea that procedural norms can serve conservative entrenchment — recalls Milgrom on institutions substituting for information, and the reader’s own work on ideology stickiness. — connects to: State admission policy can entrench policy by selectively admitting states.; Admitted states gave Republicans a lasting Senate majority core.; The 1798 naturalization delay was Federalist entrenchment against Jeffersonians. — Daryl Levinson and Benjamin I. Sachs, Political Entrenchment and Public Law, 309 (+1 more)