The 2018 races for the House of Representatives are Democrats’ best shot at regaining power in Washington. The party hasn’t had control of the chamber since 2010.

Currently, Democrats hold 194 of 435 seats, short of the 218 they need to regain control.

Let’s look at the balance of power in the House, representing each district as a dot.

Democrats need to nab at least 24 seats from Republicans to regain the majority. Here are three ways they could peel off territory.

Win districts Hillary Clinton won

Let’s line up Democratic and Republican congressional districts from Clinton strongholds on the left to solidly Trump districts on the right.

In 2016, Clinton carried 23 districts that are represented by Republicans. These districts clearly have enough Democratic voters for Democrats to be competitive.

Two South Florida Republican districts supported Clinton more than any others. About a third of the 23 split-ticket districts are in California.

But Democrats will be on defense in 12 of their own districts that voted for Donald Trump in 2016.

The three Democratic districts with the largest Trump margins are in Minnesota. Trump won one district there by more than 30 points and the two others by about 15.

But flipping Clinton-GOP seats won’t be enough: If they kept all of their existing seats and flipped every Clinton-GOP district, Democrats would still fall short.

Capitalize on retirements

About twice as many Republicans than Democrats have announced that they will not be running for their House seats in 2018.

This matters because sitting lawmakers have a sizable advantage when they run for reelection. Republicans lose that advantage when competing for open seats.

But not all of these districts make sense as targets for Democrats. They’ll probably focus on moderate districts — places where Trump lost, or won by small margins.

The seats being vacated by retiring Republican Reps. Ileana Ros-Lehtinen, Dave Reichert and Frank LoBiondo are key pickup opportunities for Democrats.

Target the districts where House races were closest

Now let’s see which House races were closest in 2016. If margins shift toward Democrats, districts across the middle of this chart would be obvious ones to watch.

As you might expect, a House Democrat won big in most areas where Clinton won big. Where Trump performed better, Republicans had bigger victories.

If we zoom in, we see that not many House races were all that competitive in 2016. Only about 30 were within 10 percentage points.

Those close Republican wins are opportunities for Democrats, but there are many close Democratic victories from 2016 that they’ll need to defend as well.

Democrats appear poised to pick up seats in the House. Whether some combination of these strategies will be enough to net 24 seats is unclear.

Historically, it would take one of the bigger waves since 1976. The party out of the White House has picked up 24-plus seats in only four of the past 10 midterm elections.

With 11 months until the midterms, look for primary challengers — or scandals involving lawmakers — to inject more uncertainty into the balance of power.