I’ve advocated for the constitutional maximum for the size of the House.
Basically, you divide a state’s population by 30,000, drop any fraction, and that’s how many representatives it gets in the House. I haven’t worked it out for the 2020 census, but it’ll definitely be more than 10,000 representatives. So about a factor of 20 more than now.
Drawback: Many representatives, but I think the pandemic has show that Congress doesn’t need to physically meet in the whole in order to get business done. Furthermore, work that is currently done by staffers could be done by elected representatives instead. And lobbyists will have a harder time and need more money to influence.
Benefit: extremely small districts are easier to contact every potential constituent by canvassing or mail, while making mass-market advertising even more inefficient or ineffective. A candidate’s local connections will be more important than their advertising budget. And outside advertising doesn’t work well when you personally know your representative.
Benefit: local groups will easily be able to get their district’s and representative’s attention. Local connections are far more influential than money.
Benefit: gerrymandering is a lot harder when districts are small. We still need more anti-gerrymandering legislation, of course. But where there’s one gerrymandered district that stretches from rural to urban, it’s very hard to draw 20 districts that do the same.
Benefit: greater diversity in Congress. One representative per 700,000 people just can’t capture the diversity within a district.
Benefit: less reason to vote based on ideology and more based on the local concerns of district. Party-line whipping is extremely difficult in large caucuses. A representative will go against their party when legislation negatively impacts their district, when a challenger only has to convince 15,000 people that they’re not representing their constituents.
Benefit: Electoral College more proportional to population. The Senate’s effect will drop from about one fifth to about one hundredth.
All of these effects will still apply if the House is increased to 1,000 instead of 10,000. I’m in favor of any increase. But I think there’s a strong case for going all the way–it will reconnect Congress to the people it represents.