So far gone were the Anti-Federalists in their irrational distrust of the new Constitution (we don’t have people like this today, right? right?) that some of them, according to Publius, actually said they feared that the Congress would not vote to enlarge the House of Representatives “as the progress of population may demand.”
Hello? As Madison points out in Federalist No. 58, it will naturally be in the interest of most members of Congress to vote for expansion of the House. Population will grow all over the place; every state experiencing growth will desire more seats in the House; the largest states and those growing fastest will lead the way, and will have the votes to make it happen; the smaller states and those growing more slowly won’t want to be left behind. Literally everything we know about normal political behavior will dictate steady growth in the House. Even senators–who represent states also represented in the House, remember?–will be inclined to vote for growth there, as it advantages their states’ positions.
Reminding us of his observations in No. 55, Madison remarks that the problem will be rather the reverse: keeping the House from growing too big to do its work in a properly deliberative fashion:
[I]n all legislative assemblies, the greater the number composing them may be, the fewer will be the men who will in fact direct their proceedings. In the first place, the more numerous any assembly may be, of whatever characters composed, the greater is known to be the ascendancy of passion over reason. In the next place, the larger the number, the greater will be the proportion of members of limited information and of weak capacities.
This is an environment ready for the demagogue: “Ignorance will be the dupe of cunnng; and passion the slave of sophistry and declamation.”
It is probably owing to similar reasoning, and fears that the House was nearing the point of diminishing returns as a working legislative assembly, that the number of members was fixed at 435 in the 63rd Congress (1913-15), and hasn’t been changed since, despite the addition of two more states since then, and enormous increases in population
(For explanation of this recurring feature, see here.)