Equal state Senate representation is the only unamendable structural feature of the Constitution.

Evidence

We live, of course, in a federal system. There is a national legislature, too: Congress. It, too, is divided into an upper house (the Senate) and a lower house (the House of Representatives). The House is elected on a population basis, but every state is entitled to at least one representative, no matter how tiny its population. There are 435 members, or roughly one for every 700,000 people. There are one hundred senators; each state has two, regardless of the size of the state or its population. California, with over 38 million people, has two senators; so do states with fewer than a million people, like Wyoming, Alaska, and Vermont. This scheme was written into the Constitution (in fact, it is cur­ rently the only provision that cannot be amended, without a state’s consent, under the Constitution’s own terms) and is immune to Baker v. Carr. — Lawrence M. Friedman and Grant M. Hayden, American Law, 448

Categorization

• XREF: Links to ch34’s note that the Supreme Court ended state legislative malapportionment via one-person-one-vote — the Senate’s equal representation remains explicitly exempt from that logic.
• DEFINE: Grounds the structural vocabulary of upper/lower houses and the federal compromise the course’s law-and-institutions readings assume.
• CANDY: A neat, self-contained fact: the Senate’s two-per-state scheme is the Constitution’s only unamendable provision without a state’s consent.