PR in the US Senate?

Currently in the US Senate, each state receives equal representation, no matter its size.

Some have proposed modifying this to give larger states more representation.

One idea would be give each state 2 sets of the following groups of senators:

  • Divide the state’s population by the population of the average state, rounding down to the nearest integer, or if zero,
  • A minimum of one senator

In other words, small states like Wyoming would still have a single senator elected in two out of every 3 biannual cycles, [2 total senators] for a 6 year term each, but larger states like California would get Floor (40 million * 50 / 330 million) = 6 senators in two out of every 3 cycles, for a total of 12 senators.

In practice, only the 4 largest states (CA, FL, TX, NY) would get more than 2 senators total, with current populations.

This means that while smaller states would still need a good single winner method, larger states should have some form of PR.

If, instead, you rounded to the nearest integer, that would give more states an extra senator (adding PA, IL, OH, GA, NC, MI to the list above).

The overall size of the US Senate would increase to ~130-140, not unmanageable, with small states still having disproportionate representation.

The Electoral College would become more representative, though still disproportionately favoring small states.

With PR, the overall balance of parties might not change drastically, since even “blue” states like CA have sizeable GOP minorities. But that might be balanced by Democratic minority representation in the TX delegation.

Anyway, I thought I would put this out there as a topic of discussion, since it would be an interesting application for multiwinner election methods, and would require a technique that could scale up to 6 or 7 winners with around 20 million voters, and who knows how many candidates.

Nice idea, but it’s not only unconstitutional but even just passing any amendment that makes it such that it’s possible for states to have different numbers of senators is unconstitutional (this is the one single thing that even constitutional amendments are not able to do).

How about Senate seats proportional to the square root of the population of the state, with a minimum of one. Or we can group small states into “regions” to make allocation more representative

The region or district idea is attractive. It would make sense to have 13 districts as in the original colonies, with 10 senators each, elected as two PR multiwinner sets of 5. Alternatively, one could have 10 districts with 14 senators each, elected as two PR multiwinner sets of 7. In any case, as in my original idea, this would require a lot of constitutional change.

Assuming one could do it, however, a Senate composed of nearly equal population districts would solve much of the disproportionality problems of the current one, with a manageable size of 130 or 140 members.

To determine the districts, a first pass idea would be to use Brian Olson’s redistricting software to divide each state into M parts (where M is the number of districts), then use those M * #state districts to assemble the M districts. One would, of course, want to weight the method to keep a district in its home state, if possible.