At this point in his presidency, Donald Trump is the least popular president in modern American history. His party trails by double digits in generic congressional polls. His biggest achievement is a law that cuts taxes for almost every American, but for most only in the short term and is less popular than any tax bill in decades, including tax hikes instituted by Presidents Clinton and Bush Sr. His long history of sexual, and racial controversies and his lack of experience in government have proven to be a major obstacle for his administration.

The Democratic Party has opposed President Trump more than almost any other opposition party in recent memory. In the past few months Democrats have won special elections in New Jersey, Virginia and, most notably, Alabama. This November, they will face off against the Republican Party in the 2018 midterm elections. They hold all the cards and enjoy a leg up in almost every political aspect imaginable.

Still, Democrats are only a slight favorite to win control of the House of Representatives, and they will most likely remain a Senate minority. Why? Three main reasons: Gerrymandering. Bad luck. Michael Richard Pence.

 

The House of Representatives

Our founding fathers designed the House of Representatives to be representative of the people, with seats apportioned by population, flexible to the national outlook, with short two-year terms. However, a process called “gerrymandering” has changed the makeup of the House. The census process, which takes place every ten years, endows state governments with the power to draw congressional districts. The ruling state party typically draws them to maximize the number of seats their party holds, strengthening their political grip for the next decade. Their strategy is to create two types of districts: one where the opposition party will win in a landslide, thus removing as many opposition voters from competitive districts as possible; and one where the favored party will be able to win in a closer election.

Leading up to 2010, Republicans developed an interesting strategy: spending record-breaking amounts of money on state-level elections. Since 2010 was a census year, they were able to gerrymander Democratic voters out of districts with competitive elections and dramatically increase the number of Republican-leaning seats in the U.S. House.

How does this impact 2018? Because there are so many more red seats than blue seats, political analyst Nate Silver calculates that Democrats may have to win the national congressional vote by as much as eight percentage points in order to gain a 218-seat, one-vote majority. Suddenly, their 11 percent lead in polls doesn’t look as good.

Prediction: Record-breaking numbers of Democrats running for office, especially women, will yield many high-quality candidates (particularly in seats held by Republicans). The Democrats will be able to capitalize on Trump’s unpopularity, but the political infrastructure will prevent a Democratic “wave.” Based on these factors, here are the predictions for the House of Representatives: Democrats 231, Republicans 204. 62% chance of Democratic takeover.

 

The Senate

The biggest factor affecting the impending Senate elections is the electoral map in 2018. The Constitution gives Senators six-year terms, so they are only up for election once every three election cycles.

In 2018, 34 Senate seats are up for grabs. Twenty-six of them are currently held by Democrats and eight by Republicans, meaning that, with one of the most difficult Senate maps in history, it will be extremely difficult for Democrats even to hold their current position.

In addition, five currently Democratic seats represent states that voted for Trump by more than 18 percentage points: North Dakota, Montana, Missouri, Indiana, and West Virginia. In order to gain the seat needed to equal the number of Republicans, Democrats would have to retain every single one of those seats and win one Republican seat.

However, a 50-50 tie in the Senate would still give Vice-President Mike Pence the tiebreaking vote, which would certainly be cast in the Republicans’ favor. To counter Pence’s vote, therefore, Democrats would need to steal two Republican seats.

There are two potential pickup opportunities: one in  Nevada, where Sen. Dean Heller will be fighting for his life in a Clinton-voting state, and the other in Arizona, where Sen. Jeff Flake is not running for re-election and the candidates for the Republican nomination, including Kelli Ward and Joe Arpaio, are radically right-wing.

Any other Democratic seat would likely come from one of three sources: Bob Corker’s Tennessee seat, Ted Cruz’s Texas seat, or John McCain’s Arizona seat. In Tennessee, Corker’s anti-Trump crusades in the Senate have hurt him to the point where he recently announced he would not be running for re-election, leaving an open seat in a red-leaning state (incumbents historically have an electoral advantage, so Corker’s retirement could help likely Democratic nominee and popular former Governor Phil Bredesen). In Texas, Cruz will be defending a red state that has slowly been growing more purple. In Arizona, McCain is not up for re-election in 2018, and his recent advanced brain cancer diagnosis suggests a likely vacancy in the Grand Canyon State.

Prediction: A path to a Senate majority through Nevada and Arizona is plausible. However, none of the seats discussed above can reasonably be considered any better than a 50/50 proposition for the Democrats. The chance of a Democratic takeover is relatively small, despite the vehemently anti-Trump political climate. Accordingly, here are the predictions for the Senate: Independents (caucusing with Democrats) 2, Democrats 48, Republicans 50. 40% chance of Democratic takeover.