WITH the Senate preparing to debate filibuster reform, now is a good time to consider a similarly daunting challenge to democratic representation in the House: its size. It’s been far too long since the House expanded to keep up with population growth and, as a result, it has lost touch with the public and been overtaken by special interests.

Indeed, the lower chamber of Congress has had the same number of members for so long that many Americans assume that its 435 seats are constitutionally mandated.

But that’s wrong: while the founders wanted to limit the size of the Senate, they intended the House to expand based on population growth. Instead of setting an absolute number, the Constitution merely limits the ratio of members to population. “The number of representatives shall not exceed one for every 30,000,” the founders wrote. They were concerned, in other words, about having too many representatives, not too few.

When the House met in 1789 it had 65 members, one for every 60,000 inhabitants (including slaves as three-fifths of a person). For well over a century, after each census Congress would pass a law increasing the size of the House.