Rep. Darrell Issa (R-Calif.) attends a news conference at the U.S. Embassy in Abuja, Nigeria, on Aug. 4, 2015. (Olamikan Gbemiga/Associated Press)

On Monday, California Republican Rep. Darrell Issa was declared the winner of a drawn-out reelection battle. And with his victory, California regained a distinction with which it is quite familiar.

For the fourth time in 12 years, not a single one of the state's 50-plus congressional districts switched parties. Just as in 2010, 2008 and 2004, every single seat returned to the party that previously controlled it.

And if you exclude the post-redistricting election of 2012, only two California districts have flipped parties since 2004. That's two out of 314 individual races — 0.6 percent. (And one of the two was a fluke in which the GOP briefly held a blue-leaning seat thanks to two Republicans advancing to the general election in 2012.)

So why do we bring this up now? Well, partly because it wasn't necessarily supposed to be this way again. Before the last round of redistricting, Californians voted for a redistricting commission to take the process out of lawmakers' hands. It was a pet project of then-Gov. Arnold Schwarzenegger (R), and it's something other states could be looking at before the 2020 Census and the redrawing of the country's lines that will follow it.

Republicans are about to hold both houses of Congress, the White House, and could soon have more allies on the Supreme Court. The Fix's Chris Cillizza explains how the balance of power in Washington rests with the GOP. (Peter Stevenson,Julio Negron/The Washington Post)

A big part of the increasing push for commissions and other redistricting reforms is the idea that these measures could root out gerrymandering — the partisan-inspired crafting of congressional district lines — and thereby increase competition and decrease partisanship in Congress.

But in the end, California might be Exhibit A in the limits of redistricting reform's impact on competition. The state's population is very segmented, and drawing competitive districts isn't easy given the self-sorting that people have done.

California's districts were actually drawn irrespective of competitiveness and partisanship. The commission decided not to even look at such data when drawing its districts, preferring to focus on what it called "communities of interest" and other demographics.

Paul Mitchell, a Democratic redistricting expert based in California, said that means the results since then are no real surprise. “When you draw lines to keep communities of interest together, you wind up creating districts that, by proxy, are partisan — as partisan as if you drew them with party labels — because you’re drawing them with values that are definitive of partisan labels themselves," Mitchell said.

None of this is to say the new map hasn't led to an increase in competitive races. Issa survived by the skin of his teeth, leading by less than one point. Rep. Ami Bera (D-Calif.), meanwhile, won by two points. The Fix rated Issa's and another GOP-held seat as toss-ups, and Bera's as potentially competitive. That's a far cry from 2010, when only two out of 52 races were decided by single digits.

But in the three elections post-redistricting, competitiveness has only ticked up slightly under the new map. And the fact that a state with 1 out of every 9 U.S. congressional districts didn't see even one change hands is pretty remarkable, on its face.

Of course, competitiveness isn't necessarily the goal of such commissions — and it may not even be a goal, like in California. Commissions, after all, are generally tasked with drawing the best, fairest possible districts. California had for the last two rounds of redistricting drawn what are known as "incumbent-protection" maps, with lawmakers going to great lengths to protect whoever was in office, regardless of party.

The commission's map, by contrast, completely uprooted many incumbents, drawing them into districts together, making their districts much tougher and creating new open seats. More than a dozen members retired or lost.

“What we had with the redistricting commission was not all for naught for reformers," Mitchell said. "We had a ton of disruption and a huge amount of competitiveness in 2012, but it wasn’t long-term competitiveness.”

And that's real the takeaway here. Gerrymandering is increasingly viewed as a political ill that must be dealt with. And there is generally considerable public support for redistricting reforms whenever they are on the ballot.

But given our increasing tendency to live around people with whom we share a worldview, creating competitive districts often requires its own brand of gerrymandering that doesn't jibe with grouping people who share things in common.

The election reform group FairVote called it back in 2013: "California's citizens have taken away from the politicians the power to choose their voters, and that was reflected in the high incumbent turnover in 2012. But no matter who is drawing the lines, the polarization of the American electorate makes achieving competitive single-member districts effectively impossible on a large scale."

The goal of California's commission wasn't necessarily to create a bunch of toss-up races every year. But it does show how elusive that goal can be — even when things are more "fair."

And for those who'd like to make their members of Congress squirm on Election Day a little more often, that's worth remembering.

Correction: This post initially said no incumbents in California had lost. Rep. Mike Honda (D-Calif.) did lose, but to fellow Democrat and Rep.-elect Ro Khanna.