Bicameral

Bicameral comes from the Latin for two chambers. A bicameral legislature splits its lawmaking body into two separate houses that must both agree before anything becomes law. America's are the House of Representatives and the Senate.

At the Constitutional Convention in 1787, the split solved a bitter fight. Big states wanted representation by population; small states wanted every state equal. The Great Compromise gave each side one house: the House apportioned by population, the Senate with two seats per state regardless of size.

But the two houses serve a deeper purpose than just balancing big and small states. There is a famous story, perhaps too neat to be entirely true, in which Jefferson asks Washington why the convention created a Senate. Washington asks why Jefferson just poured his coffee into his saucer. To cool it, Jefferson says. Just so, Washington replies, we pour legislation into the senatorial saucer to cool it.

Whether or not those words were ever spoken, they capture the design. The slower, smaller Senate was meant to be the saucer, the place where the hot passions of the moment, rushing out of the larger House, could cool before becoming law.