\nFact: interest groups, not individual voters, are and must necessarily be the building blocks (building blocs?) of liberal-/representative-democratic politics. It would be absurd and infeasible for a mass candidate or party to appeal to each voter individually without reference to some broadly shared characteristic or material interest. Ergo, anyone who complains about “interest groups” as a whole having too much influence is either ignorant or pulling your leg.
The major difference between various liberal-democratic systems is not how much they are under the sway of “interest groups,” but whether the coalition-building between those interest groups’ representatives to create a voting (and governing) majority is something that happens behind closed doors or in public. The United States, with its legally enforced two-party system, is on the hard former end of the spectrum; systems with proportional representation tend toward the latter. I really don’t think proportional representation actually changes the baseline electoral calculus all that much, but I do think it’s a generally positive thing to have your demands, concessions, and compromises laid out in the light of day.
Note that this doesn’t exclude the possibility that one particular interest group will end up with vastly outsized influence just due to the way things mathematically align. But the phenomenon of the minority “kingmaker” is not, I think, one exclusive to systems with many small parties. You could probably find any number of examples in American politics, it’s just that the system’s extreme political obscurantism renders it considerably more difficult.
I don’t think closed/open negotiations are the key here I think a lot has to do with representational and principal/agent problems
Like what the Democrats were thinking in the 70s and 80s was
“Our base is labor, that PLUS blacks and women that’s an unstoppable majority” but in practice that cashed out as “if we get all the unions PLUS the NAACP and NOW to endorse us\u2026”
And that didn’t factor in that a lot of “labor” was also the interest group of “white ethnic men” and that a lot of “women” were organized through churches and not NOW
Really Bill Clinton’s power was to resolve this by integrating these interest groups through personal connection. In Arkansas he came from a [poor white] background close with [poor blacks] and became a [good ol’ boy local elite]. Expanding nationally, he was an [Oxford-certified meritocratic elite] who was closely entwined with a [feminist professional]. By all appearances, he was a keystone in bonding [Hollywood celebrities] and the [nonprofit sector] and [tech finance/elites] around the rockstar [male sexual liberty to fuck teenagers].
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