As North Carolina’s redistricting reformers continue to make their case, a new Bloomberg Businessweek article discusses one potential impact from congressional election map gerrymandering that the map drawers probably did not anticipate.

To create as many solid Republican seats as possible, GOP lawmakers did what the party in power has done for decades: They created strangely shaped districts that lumped Democrats into a handful of deeply blue enclaves the GOP was resigned to losing, and then drew the other districts to spread Republican votes everywhere else. Pennsylvania, which Princeton Professor Samuel Wang calculates was the most gerrymandered state, is emblematic of the results: In 2012, Republican House candidates in Pennsylvania won 13 seats by an average of 22 percentage points; Democrats won five seats by an average margin of 53 percentage points. Wang, a neuroscientist whose statistical models accurately predicted the 2012 presidential election results, says nationwide, post-Census gerrymandering in 2011 rendered about 1.7 million Democratic votes superfluous because they were funneled into existing blue spots on the map.

There’s a superficial logic to this strategy, but trouble lurks underneath. Many of the redrawn districts that elected Republicans in 2012 aren’t actually conservative strongholds, Wang says. They’re also packed with political independents whose votes tend to reflect the national mood. They’ve tilted toward the GOP in recent years but don’t think of themselves as Republican loyalists. “When they swing,” says Wang, “they swing really hard against you.” In the aftermath of the government shutdown, just 35 percent of independents said Republican control of the House was “good for the country,” down from 54 percent last December, according to a poll by CNN/ORC International conducted on Oct. 18-20.

That sharp shift could mean gerrymandered districts are actually less secure than those that weren’t subject to partisan cartography after 2010.

This analysis reminds me of an observation from a 2011 CarolinaJournal.com column on redistricting.

Observers should avoid the additional mistake of framing the merits of the new maps in terms of their likely impacts on a single election involving current incumbents. Could Republicans swing as many as four races from the “D” column to the “R” column with the new maps? Potentially. But that outcome is certain only in Republicans’ wishes and Democrats’ nightmares. That outcome assumes that Republicans would hold all existing districts and pick up every targeted Democratic seat. Elections rarely follow such a one-sided course.

Would the new maps guarantee that Republicans could hold a 10-3 — or even an 8-5 — advantage in North Carolina congressional elections for the next decade? Hardly. To make some districts “more” Republican, it’s necessary to make other districts “less” Republican.

A GOP representative other than Walter Jones would face a stiff battle to win the new version of the 3rd District. Piedmont districts previously packed with Republicans, thanks to Democratic mapmakers in 2001, would have more Democrats now. Those elections would no longer represent the slam-dunk victories the GOP has counted on for the past decade.

Wake Forest University political scientist John Dinan concluded recently that “the proposed map would increase the chance that a district could be won by the party not currently holding the district” in eight of the 13 districts. Republicans now hold the seats in four of the eight districts Dinan labels as more competitive under the proposed plan.

In other words, the new map could give Republicans a 10-3 advantage under the absolute best circumstances for the GOP. But another Democratic tide like the one witnessed in 2008 could allow Democrats to build just as large an advantage within the state’s congressional delegation.