Corrected Nov. 16 | Republicans got a boost in the race to gain control of the House in this year’s elections because they held on to their advantage in redrawing congressional maps and got some key rulings from courts, experts said.

While both political parties have drawn maps that favor their candidates, experts said Republicans used the redistricting process after the 2020 census to retain a small, but measurable, advantage over Democrats in the midterm election.

More than a dozen races were still not called Monday, but it appeared Republicans were closing in on the 218 seats needed to take control of the chamber from Democrats — a result that means a change in just a few seats would make the difference.

In such an outcome, advantages in redistricting “almost certainly” contributed, said Michael Li, senior counsel for the Brennan Center for Justice at New York University Law School, who focuses on elections.

“It’s almost certain the way the maps were drawn, and the skews that exist in the maps, will play an outsize role,” Li said. “If Republicans win a majority there will almost certainly be a majority because of redistricting.”

Li said Republican control in places like Texas and Florida helped shore up Republican advantages in the maps.

Christopher Warshaw, an associate professor of political science at George Washington University, said the maps drawn by legislatures in Texas and Florida were “clearly helping Republicans,” who now will have three more GOP-held congressional seats across the two state delegations.

But he said it was more difficult to pinpoint redistricting as the reason Republicans would get control of the House, with partisan redistricting on both sides in such a close election.

“I think it is worth pushing back on what people on Twitter are saying of, ‘Oh, this one state made the difference in the majority,’ when Republicans won the national popular vote,” Warshaw said. “It seems like this year Republicans won a majority of the votes, but the most small ‘d’ democratic result is they win a majority of the seats.”

Republican advantage

Last week, voters went to the polls in districts that favored Republicans less than they did a decade ago, but the maps still favor Republicans overall, experts said. Partisan mapmakers can carve up the state in a way that gives their candidates the best chance of winning.

The decreased advantage for Republicans is partly due to long-term efforts to take redistricting out of the hands of state legislators in favor of nonpartisan commissions in states such as Colorado, Li said.

Republicans for the 2022 midterms controlled the line-drawing process in 20 states, compared with 11 for Democrats, according to a Pew Research Center analysis.

A decade ago, Republicans controlled the process in 22 states. Since then, Republicans have lost control of some legislatures, like Pennsylvania, others like Michigan have gone to commissions, and apportionment losses in places like West Virginia took seats out of mapmakers’ hands.

In states where Republicans and Democrats drew congressional lines, they concentrated more on protecting safe seats and incumbents this cycle, according to David Canon, a political science professor at the University of Wisconsin.

Canon called the results a “surprisingly status quo election” because of how redistricting ended up protecting many incumbents. The few competitive races largely came from states with maps drawn by nonpartisan commissions.

“If you look at the exit polls and how ticked-off voters are, you would think this would be a really bad year for incumbents,” Canon said.

In 2012, the first election after the 2010 census redistricting cycle, Democrats won 1 percentage point more of the vote nationally, but Republicans won a 234-seat majority.

This year, Republicans are on a path to win the national popular vote by about 1 percentage point, which could mirror a small House majority, Warshaw said.

Democratic-drawn maps helped that party’s candidates in Illinois, Nevada and Maryland. But Warshaw pointed out that court decisions in other states that broke in favor of Republicans might have washed out those advantages.

Court involvement

Over the course of the redistricting process and dozens of lawsuits, courts tossed Republican-favored maps in North Carolina and Democrat-favored maps in Maryland and New York. Separately, courts in Pennsylvania mandated a court-drawn map after legislative deadlock.

But a few court fights ended up favoring Republicans.

In Ohio, the state Supreme Court threw out several legislatively drawn maps for unfairly favoring Republicans — but the court does not have the power to force a new map on the legislature, so they were used for the midterm election.

Prentiss Haney, co-executive director of the Ohio Organizing Collaborative, argued that a “fair” Ohio map would have about seven Republicans and six Democrats, up from the five who won last week. The court fight brought some progress from the initial 12-2 split that mapmakers proposed, Haney said.

“While it is not fully representative of Ohio’s choices it is far better and gives more opportunities than what we had in 2012,” Haney said.

The New York Supreme Court also tossed a Democratic-drawn map where former President Donald Trump would have won four of the state’s 26 congressional seats. In last week’s elections under the court-approved map, Republicans have won seven of the state’s 26 seats, with one race still undecided.

The U.S. Supreme Court also allowed Alabama to use a map that a lower court ruled had violated the Voting Rights Act for having only one Black opportunity district in the state. Following that ruling in February, pending a broader argument over the VRA, courts allowed Louisiana and Georgia to move forward with maps found to similarly violate the VRA.

Adia Winfrey, co-founder of Black voting rights group Transform Alabama and previously one of the plaintiffs in the VRA suit in the state, pointed out that a favorable map does not guarantee success.

Winfrey said that even if the Supreme Court sides with voters to mandate a second Black opportunity district in her state, organizers like her would still have to push voters to show up at the polls.

“Yes, having fair maps is important, but even more important than the maps is the turnout,” Winfrey said.

Warshaw pointed out that redistricting will continue after this election, even in the absence of Supreme Court rulings on the Voting Rights Act. There is a pending redraw of maps in Ohio and North Carolina that could net Republicans as many as five seats in 2024.

“The story of redistricting is still being written here,” Warshaw said.

This report was corrected to accurately reflect the role of Adia Winfrey in a lawsuit.