In June, after House Democrats lost a hotly contested special election in Atlanta, they insisted that control of the chamber was within their reach in 2018. But the stars had to align just right.

Since then, Democrats think the stars have done just that.

House Republicans are retiring from key districts, the federal courts are ruling in Democrats' favor on redistricting cases that could reshape key swing-state maps and polls consistently show Americans favor a nameless Democrat over a nameless Republican. Plus, the mere fact that Donald Trump is president (not to mention historically unpopular at this point in his tenure) could help more Democrats get elected this fall.

House Democrats' campaign arm now says they're targeting some 90 Republican seats in November's midterm elections. Democrats need to net 24 seats to take back control of the House.

Taking 90 seats may be overly optimistic, but Democrats have been cheering a week's worth of news that could set them up for a shot at taking back control of the House for the first time in nearly a decade. Here's what has them excited:

Top Republicans are retiring: One of the richest members of Congress. One of the most powerful Republicans on foreign affairs. One of the most politically ambitious Republican lawmakers.

Those are just three of nearly 30 House Republicans who have decided to retire. It's more retirements than anytime in the past decade. A number of the lawmakers leaving, as The Post's Mike DeBonis outlines, are committee chairmen, raising the question of: Why decide to leave at the height of your power?

Some of these departures could make potentially significantly easier for Democrats. Rep. Darrell Issa (Calif.) is one of the richest members in Congress and could have spent unlimited money on a reelection campaign in an increasingly liberal San Diego-area district. But now that he won't be running for reelection, Democrats have a serious shot at flipping his seat.

Same with retiring House Foreign Affairs Committee Chairman Edward R. Royce (Calif.), who is leaving one of the most pro-Hillary Clinton Republican-held districts in the nation after holding it for more than 30 years.

Democrats are killing it in polling right now: If you had to choose right now between electing a Democrat or a Republican to Congress, even if you didn't know their names, who would you choose?

In a series of polls over that have asked this over the past month, voters say they'd choose a generic Democrat over a generic Republican by 13 points. That's more than double what election forecasters say Democrats need to be polling right now to take back the House. Republicans seized control of the House in 2010 when polling showed voters favored them in this same scenario by just six points.

Judges are ruling in their favor on redistricting: In 2010, Republicans won control of state legislatures and governor's mansions across the country, thus had the power to draw congressional and state legislative districts. But now courts are ordering Republicans to redraw more nonpartisan maps, just in time for the 2018 election.

A federal court just forced North Carolina lawmakers to redraw the lines of all 13 congressional districts to make them more nonpartisan. It was the first time that a federal court struck down a congressional map for partisan gerrymandering (as opposed to racial gerrymandering).

The Supreme Court will soon decide on a similar partisan redistricting case involving Wisconsin's state legislature, and another case in Pennsylvania is pending.

If this line of litigation is successful, Democrats could have an opening to challenge maps across the country in time for 2018.

Republicans control Washington: This is a simple fact, but it shouldn't be overlooked with how it plays into voters' decisions this November.

Because Republicans control so much of government, they have less places to shift blame if what comes out of Washington is unpopular. And so far, Republicans' only/major legislative accomplishment, a tax plan, is unpopular — 52 percent of Americans disapprove, according to a new Quinnipiac poll.

(Republicans are pretty sure they're on the right side of things. See: Walmart raising its starting hourly wage from $9 to $11 and giving credit to savings it expects from the new corporate tax plan.)

Republicans couldn't manage to repeal Obamacare last year, but they did undo a key part of it via the tax bill and by executive order. Health-care experts predict those actions could spike premiums for some people, putting Democrats in a position to blame Republicans for people's health care, too.

Even an executive order such as ocean drilling could endanger House Republicans. It's turning out to be unpopular among a bipartisan group of lawmakers, and many of the most vulnerable Republicans are trying to run for reelection in coastal states.