The delegates at the Constitutional Convention that the republic they were trying to establish could not survive if the people were not adequately represented.
They unanimously agreed that each state should be entitled to one representative for every thrity thousand, but when the Article 1 Section 2 Clause 3 was transcribed a serious error was made, Instead of limiting the number of constituents, the clause indicated that the number of representatives could not exceed one for every thirty thousand.
The delegates intended to have the clause limit the number of constituetnts assigned to each representative but the man who transcribed the document wrote the number of representatives shall not exceed one for every thirty thousand.
Congress tried to tix the problem when the first amendment they proposed in the Bill of Rights was an attempt to clarify the issue of apportionment in the House of Representatives.
So basically, it now requires a Constitutional Amendment! I do not see today's politicians being in favor of diluting their power. Constitutional Conventions can be risky. If passed it would give us 10,000 U.S. Representatives. ( my rough math, maybe more) I guess we are more than 30,000 per Rep. now, eh?