Quoting Senator Yankee's post that ultimately turned me against this amendment, and why I am urging the Senate to reject it now:
I will oppose this proposal. The At-large Senators as a collective group are meant to represent the popular majority, but this is done in 11% increments if that makes sense, which itself ensures that various constituencies and ideologies are represented and have a seat at the decision making table.
The reason why we moved away from the pre-reset setup here was for good reason and that is because it basically ensured that for some months of time, the people who elected a given At-large representative would go unrepresented, by changing the electoral threshold by which that seat is chosen.
11, 11, 11, 51, 11
The basic effect of this is that the same group, same ideology would almost invariably win every special election ever, regardless of which seat they are filling. This would always then distort the distribution of seats in the At-large class, giving that side an extra seat, that would barring a turnout failure usually flip back (or another one in its place) to the people who held it previously.
51% cannot pick a seat that can be won with an 11% subgroup in a normal election, without screwing that sub group out of its representation. This basically turns thus into a power grab as such.
As for why the party chairs do it, there have been mechanism under the current setup, by which parties pick the members for the Chair to appoint through some kind of primary, but more importantly it comes down to timing and efficiency as a complex process could very well break down. Either way that determination should be made by the party bylaws not forced from the top.
