As Americans head to the polls for the historic 2018 midterm elections, Democrats appear poised to take back control of the United States House of Representatives, according to the final generic ballot polls, which ask voters simply if they plan to cast ballots for Democrats or Republicans without naming a specific candidate. But due to partisan gerrymandering, simply winning a majority of the popular vote will not be nearly enough to win the number of seats required to gain control of the House. In fact, according to one study reported by Vox, Democrats would need to win by 11 points in order to pick up the 24 seats that they need for House victory.

However, not all experts agree that the hill Democrats must climb is quite that steep. Dave Wasserman of Cook Political Report says that by his analysis, a popular vote victory — that is, a generic ballot lead — of about 7 percent should be enough to get Democrats over the line.

The final polls of likely voters leading up to Tuesday’s election show Democrats doing just that. According to an NBC News/Wall Street Journal poll issued on Saturday, Democrats head into election day with a seven-point lead, with 50 percent saying they will vote for Democrats and just 43 percent planning to vote for Republicans.

At the same time, a CNN/SSRS Research poll released on Monday showed a 13-point lead for Democrats, 55-42.

Democrat Adam Schiff will become Chairman of the House Intelligence Committee if Democrats take back control of the House. Featured image credit: Mario Tama Getty Images

Gerrymandering occurs at the state level when the party that controls a state legislature redraws the lines of congressional and legislative districts in a way that makes it easier for that party’s candidates to win more seats with fewer votes, as The Las Vegas Sun explained. With Republicans in control of 31 state legislatures, the Washington Post reports, compared to just 14 controlled by Democrats, the GOP has granted itself a significant advantage in congressional elections.

“It’s breaking the rules of the game, breaking the rules of the system so that your party remains in power,” Michael Li of the Brennan Center for Justice at New York University told The Sun. “We’ve seen this increase to frightening levels.”

Nonetheless, in overall polling, Democrats remain in solid position to retake the House, though possibly by a close margin. According to the statistical prediction model designed by FiveThirtyEight, coming into election day, Democrats hold an 87.8 percent, or seven-out-of-eight, chance of at least winning a slim majority in the House, while Republicans have just a one-in-eight, or 12.2 percent chance of retaining their hold on power there.

In the FiveThirtyEight average of all generic ballot polls as of the morning of November 6, Election Day, Democrats led Republicans by 8.7 points, 50.7 to 42.