With Republicans pushing a legal doctrine that could radically reshape elections, it’s easy to dismiss the effort at the Supreme Court this week as a Republican power grab. It’s worth asking, though, whether the effort could backfire on these Republicans.

The director of the Texas Politics Project, Joshua Blank, tells the Sun that an adoption of the fringe independent state legislature theory could have unanticipated consequences across the board.

“When people start to think about changes to the electoral system they tend to oversimplify them,” he said. “There tends to be an expectation that a particular change would lead to a particular outcome, and that’s usually not the case.”

The independent state legislature theory holds that the state legislature and only the state legislature has the power to decide the rules for elections in each state. In practice, it means that state legislatures would not be subject to oversight by state constitutions and state courts, and would only have to comply with federal election law.

The case in question, Moore v. Harper, originates from North Carolina, where the state supreme court struck down a gerrymandered district map drawn by the state legislature. The map that was struck down was a Republican gerrymander that would have netted Republicans two seats in the House at the cost of two Democratic seats.

The state’s legislative leaders then appealed the case to the Supreme Court, arguing — based on the independent state legislature theory — that the state court did not have the authority to strike down such a map.

Because Republicans are the ones arguing in favor of the theory, the conventional wisdom is that a Supreme Court ruling backing it would largely benefit the GOP. This may not be the case, though, and to illustrate why, it makes sense to look at the states where legislatures already control the redistricting process.

Many deep-red states like West Virginia, Wyoming, and Montana don’t offer any opportunity for Republicans trying to squeeze more seats out of their states because they are already gerrymandered to such an extent that they only send Republicans to the House.

In some key states for Republicans — like Texas and Florida — the legislatures already control redistricting, and giving those bodies supreme authority over elections and redistricting wouldn’t radically reshape the processes.

In fact, Republicans gained seats in Florida this year not through the legislature but because Governor DeSantis redrew the map after he vetoed the legislators’ map.

Florida’s state legislators first put forward a bipartisan map that favored incumbency at the cost of more Republican seats, a map that would now be law if the governor had not gotten involved.

The electoral maps of deep-blue strongholds like California and New York, on the other hand, are generated by independent commissions, meaning an adoption of the independent state legislature theory would greatly empower lawmakers in the redistricting processes there.

New York legislators attempted to pass a more partisan Democratic district map in 2022’s redistricting after the commission failed to generate a map, but were prevented from doing so when the state Republican Party sued to block their move.

This litigation was decided by the state’s high court and relied on an amendment to the New York state constitution, both of which could be irrelevant if the new theory were adopted.

In California, the electoral commission generated a map fairly similar to the previous one, enabling Republicans to hold onto some of their seats there. Republicans even gained a seat, despite Democratic campaigns targeting at least five Republican incumbents in light-red districts. In the final tally, the Democrats lost two seats and Republicans netted one. One Democratic seat was lost to reapportionment.

In Florida, New York, and California alone, Republicans managed to flip seven of the nine net seats they gained in 2022. In all of these states, Republicans were helped in the redistricting process by an entity other than the state legislature.

In a world where New York and Florida legislators got their way instead of an independent commission or the governor, Democrats could have ended up retaining a 219-seat majority in the House on the backs of these two states alone.

While Republicans might owe their current House majority to non-legislative redistricting processes, that doesn’t necessarily mean that adopting independent state legislature theory would deliver the majority to Democrats, either.

Legislators have different incentives than just their partisan connections, as was demonstrated by the initial plan proposed by Florida legislators. For them, making their current seats safer was more important than picking up more seats for the party.

Mr. Blank said Texas is a good example of this phenomenon. Texas is gerrymandered to benefit Republicans, but in this year’s redistricting process legislators didn’t propose a particularly aggressive map after losing a bitter battle in the previous redistricting debate.

Texas Republicans drew an aggressive map for state level offices in 2012, Mr. Blank said, which helped them secure a larger majority in the short term but set the stage for Democratic gains later in the decade.

Although Republicans got more seats in the near term, it came at the cost of those seats being less safe for Republican incumbents. As the populations of those districts and the political climate shifted, Democrats were able to challenge what were previously safe Republican seats.

This year, he said, they opted to propose a less aggressive map, which still favors Republicans but minimizes the risk of incumbents losing their seats due to changing political tides throughout the decade.

What might end up being even more disruptive than any redistricting fights, in the opinion of a political scientist at the University of Florida, Michael McDonald, are the changes the theory could have on the voting process.

“If the court were to rule in favor of North Carolina’s position, there would be major disruptions in elections,” Mr. McDonald tells the Sun.

In an extreme scenario, state legislatures could create two separate election tracks or processes. Mr. McDonald says that a legislature could theoretically dictate that state elections are to be held only by mail, for example, while federal elections are to be held only in person.

In terms of generating an advantage for one party or another, it’s hard to say which party would benefit more from the Supreme Court adopting the theory, though it’s possible to make a case for either.

What’s clear is that adopting this theory would toss a bomb into electoral politics in America, the effects of which would depend on the specifics of the ruling and what legislators decide to do in its wake.