The challenge to the new Idaho redistricting plan led by Twin Falls County Prosecutor Grant Loebs (joined in by a bunch of other jurisdictions) is in, and there's been some review of it - and some support in places like the Twin Falls Times News editorial page. There is no perfect way to predict what the Idaho Supreme Court might do; it has a way of surprising on redistricting cases. But from here, the core argument before it doesn't look especially solid.
The Times News describes it succinctly, and it goes like this. The parameters of a redistricting are bound by three sets of terms. There's the U.S. Constitution, at the highest level, which requires (according to Supreme Court interpretations) adherence to the "one man, one vote" principle - meaning that districts should have as close as practical the same number of people (or at least electors). Second, there's the state constitution, which has a similar requirement calling for as few counties as practical to be split. And third, there are a series of laws (and legal cases, which the editorial doesn't make clear) which also have to be considered - things like maintaining communities of interest, not overtly benefitting specific parties or individuals, no overt gerrymandering, care not to disenfranchise certain minority groups (notably Indian tribes in Idaho's case), and others.
The editorial: "If you accept the fact that a state law can never trump the state constitution, the map becomes a lot easier to draw. The current plan that was created by the redistricting commission carves up counties more times than they needed to be. This is where Loebs’ suit makes its stand, and it’s an approach we have a hard time arguing against."
Maybe you already see the logical problem here.
If redistricting is simply a case of absolute trumps, then the state constitution need not apply at all. Rather, you adopt - as a matter of requirement - whatever plan you can draw that split's Idaho's population into 35 equally populated districts. Because, if Loebs' trumping argument is right, then only "one man, one vote" comes into play. Anything else would dilute the mandate of the U.S. constitution.
As a matter of history, the courts haven't looked at it that way. Reasonably and practically, they've allowed for a degree of give and flexibility in the system. As an informal guide, redistricters have found that courts will usually accept plans that have about a 10% or less deviation in population between the most and least populous districts. That means a number of plans could be considered reasonable and practical. That's what allows us to even get to a consideration of what the state constitution says.
The same principle seems to apply to splitting counties. If you split too many counties, that could be a basis for rejecting a plan. But how many is too many? Consider this from the reapportionment commission's report on its plan:
a. 1 county has a population that it can constitute a single district by itself without combining with any other county or portion of another county. It is Bingham County.Bingham County occupies a unique position within Idaho because it is surrounded by counties that must either be split or combined with other counties and contains a portion of a Native American Reservation, the remainder of which is located in three other counties (Power, Bannock, and Caribou).
b. Two counties could be divided into districts wholly within that county that meet the one person/one vote requirement without having to combine any portion of that county with any other county or portion of another county. They are Ada County
and Kootenai County.
c. Four counties are of such population that one or more districts can be created solely within the county, but a portion of the county must be combined with other counties to meet the one person/one vote requirements. They are Bannock County,
Bonneville County, Canyon County, and Twin Falls County.
d. The remaining counties are so sparsely populated that they must be combined with other counties to create districts of sufficient population to comply with the federal constitutional requirement of one person/one vote. One of these counties
(Bonner) must be divided and combined with contiguous counties because one neighboring county (Boundary) is not contiguous to any other county."
There is no way, in other words, to split fewer than five counties in crafting a plan, the commission said. It could do that (which seems to be where Loebs is headed). But are the current plan's 11-county splits (of 44 counties, remember) really too many - if it means you rapidly start throwing out all the other considerations a redistricting plan should include? It seems here, probably not.
There's some gray area, as so often the case in this mathematical-based exercise. But the Supreme Court may wind up considering this as well: If it gives such strong primacy to a plan that places such strong emphasis on just one reapportioning goal, it's apt to generate more lawsuits on the basis that others were not considered. And lawsuits on those kinds of bases have worked, from time to time, as well.