What do folks think the correct answer to this question is: How does the size of an assembly affect the strength of political parties?
By strength, I mean the relative freedom of the individual member to cultivate constituency ties and to dissent from party leadership on votes on legislation. I also mean, holding other factors constant.
Suppose a country’s assembly is significantly smaller than its expected size, per the cube-root law. If nothing else changes, how would raising the size be expected to affect the strength of parties?
Obviously, I am thinking about potentially expanding the US House, so a starting point of non-hierarchical parties, and only two of them (and presidentialism, etc.). But I am interested in the question more broadly, and whether features of US party and legislative politics, aside from the small House size, change the impact of increased size on party strength in a manner that might be different from how it would play out in other contexts.
I ask because I genuinely do not know. I could see it going either way. A larger house, for a given population, means each member represents fewer voters, obviously. This could make personal-vote and constituency-service strategies more viable, thereby in some sense making parties “weaker”. On the other hand, a larger assembly (here, independent of population) makes internal collective action more challenging. This could result in members delegating (or simply losing) more authority to internal party leadership, making parties “stronger.” Note that these possible directions of change are closely connected to the two factors that go into the cube root law itself–this is a logical model that is based on balancing (and minimizing overall) two types of “communication channels”: those between legislators and constituents, and those among legislators themselves.
It is possible both directions of change can happen at the same time, implying parties get weaker in some ways and stronger in others. That is, more constituency-oriented behavior, but also more party leadership control over votes and especially over speaking time. I am not sure what that means for overall strength. Maybe that isn’t even the right way to frame the question; skepticism over my own question framing is why I use the inverted commas in the title of this post.
Finally, theoretically and all else equal, a larger assembly means more parties should be represented (per the Seat Product Model). I have my doubts that this would be realized in the US, however, given all the other barriers to third-party representation. Unless the House were truly huge, I do not expect much impact there as long as it is elected in single-seat districts, and with primaries (or with “top two”/”top four” rules). However, parties’ internal strength could be affected. But which way?