Federal courts shape state common law far less than institutional prominence suggests.

Evidence

But federal courts have considerably less influence on common-law policymaking. … But federal courts decide such a miniscule proportion of common-law cases that their opportunities for influence are quite limited. — G. Alan Tarr, Judicial Process and Judicial…, 3533

Categorization

• XREF: Qualifies the assumption that federal courts drive legal development; pairs with the vertical-influence discussion in earlier chapters.
• DEFINE: Clarifies the distinction between common-law policymaking, where precedent is the only text, and constitutional policymaking.