Democrats are currently on track to retake the Senate, according to the latest polls —though they don’t have much room for error.

If Hillary Clinton wins the presidency, her party would need a net gain of four seats to take over control of the chamber. And just a few months ago, the party had a clear advantage in polls of just two contests.

But the combination of Donald Trump’s nomination and a strong recruitment effort has bolstered Democrats’ chances. Here’s the good news the party has gotten lately:

Democratic candidates appear to be solidly ahead in three Republican-held seats — Illinois, Wisconsin, and Indiana. And since the conventions, Democrats seem to have gained narrow leads in two more — Pennsylvania and New Hampshire.

Another GOP-held seat, in North Carolina, looks like a toss-up at this point.

Still, the party doesn’t appear to be in landslide territory just yet, since Republicans have gotten some encouraging news too:

Democrats are narrowly losing one of their own seats, in Nevada.

In the remaining competitive races for Republican-held seats — Florida, Ohio, Missouri, Arizona, and others — GOP candidates remain ahead.

So if the results shake out like that, Democrats would end up with a net gain of either four or five seats, depending on what happens in North Carolina — enough to take control.

But of course, much can change in the two and a half months until Election Day. Many of these current margins are quite narrow. In recent cycles, several eventual Senate winners only emerged with clear poll leads in September or October. And in a couple of recent races, polls ended up being very wrong.

Still, the overall map is so favorable to Democrats this year — only 10 Democratic-controlled seats are up and only one is seriously contested out of 34 total — that Republicans essentially have to play whack-a-mole to try to minimize their losses. And Trump is making that difficult game even tougher.

The solid Democratic leads: Illinois, Wisconsin, and (for now) Indiana

Illinois has long appeared to be Democrats’ best pickup opportunity. It’s an overwhelmingly Democratic state voting in a presidential year, so Sen. Mark Kirk (R) — who won just narrowly in the 2010 Republican landslide — has a big disadvantage against Rep. Tammy Duckworth (D), a veteran who lost both her legs in Iraq.

Kirk has denounced Trump and is running ads making that clear to Illinois voters, but few expect that will be enough to save him. Most observers still view this as a near-certain Democratic pickup, though public polling of the race has been sparse.

Wisconsin, where former Sen. Russ Feingold (D) is campaigning to retake his former seat from the incumbent, Ron Johnson (R), has also been viewed as a highly likely Democratic pickup for months, and that remains the case. Unlike in Illinois, Republicans did at least have the hope that Donald Trump would make this state competitive, but that appears not to be happening (he trails Clinton by double digits).

And unlike many other GOP Senate candidates, Johnson hasn’t managed to significantly outperform Trump in the polls — they’re down by nearly the same margin. This is likely because Johnson has developed a reputation as an arch-conservative and seemed to embrace Trump earlier this year, saying "Ronald and the Donald" could campaign together (in a sound bite that delighted Democrats). Lately, Johnson has been trying to distance himself from the nominee, but it may be too late.

Then in Indiana, the mid-July entry of former Sen. Evan Bayh (D) into the race for his old seat was a massive coup for Democrats, instantly turning a third-tier pickup opportunity into a top-tier one. One Democratic strategist running down the races for me placed Indiana just after Illinois and Wisconsin as the three contests where Democrats’ chances currently look strongest.

Indeed, Bayh starts off with a sizable poll lead over his opponent for the open seat, Rep. Todd Young (R) — 7 points in a recent Monmouth poll, and more than 20 points in polling that’s been released from Democratic campaign groups. And he had nearly $10 million sitting in his campaign account from last time — nearly eight times as much cash on hand as Young at the time of the last campaign finance filings.

But Bayh has only been in the race since mid-July, after all, and there are a few reasons his lead might not last. First, Indiana currently looks like one of Trump’s stronger states — he’s up by 11 points over Clinton in one recent poll — so Bayh may not get the same help from the top of the ticket that Democratic candidates in other swing states might. And second, Bayh could be vulnerable to attacks related to how he’s spent his past few years — he made millions altogether working for a lobbying firm and a private equity firm, and sitting on corporate boards, and there are questions about his residency.

The next Democratic hopes: Pennsylvania, New Hampshire, and North Carolina

After those three races, Democrats have gotten encouraging polling news lately in three presidential swing state contests in particular.

The story in both New Hampshire and Pennsylvania appears to be pretty simple — Donald Trump is now not just losing but getting blown out, and the incumbent Republican senator is being dragged down with him.

Both Sen. Kelly Ayotte (R-NH) and Sen. Pat Toomey (R-PA) are polling well ahead of Trump — but that just isn’t enough anymore considering how far Trump is down now. Their challengers — Gov. Maggie Hassan (D-NH) and Katie McGinty (D-PA) — have now led all the polls in the past few weeks, though sometimes quite narrowly.

So watch how Ayotte and Toomey try to grapple with the Trump question in the next few weeks. So far, both have been critical of Trump, but Ayotte has said she’s voting for him and Toomey says he hasn’t made up his mind yet.

Then there’s North Carolina. Right now the state looks somewhat more competitive on the presidential level, but Clinton appears to have the upper hand. Beyond that, the current GOP governor is facing a difficult reelection in part due to the controversy over the state's transgender bathroom law, and two-term incumbent Sen. Richard Burr (R) hasn’t particularly distinguished himself in office.

Democrats are hoping that their candidate, former state House member Deborah Ross (D), can upset Burr like Kay Hagan did to then-Sen. Elizabeth Dole in 2008. But Republicans are hoping to paint Ross, who was state director of the American Civil Liberties Union, as a far-left extremist. This looks like a very tight race right now — for instance, one recent poll showed Burr running 7 points ahead of Trump but still losing to Ross by 2 points.

The GOP’s one pickup opportunity: Nevada

Since this year’s Senate elections are six years after the 2010 Republican midterm landslide, the GOP is on defense far more than it is on offense. Republicans have only managed to put up a somewhat formidable candidate in one of the 10 Democratic seats up: Nevada.

With Senate Democratic leader Harry Reid retiring, his seat is up for grabs, and polls show a very tight race between Rep. Joe Heck (R) and former state Attorney General Catherine Cortez Masto (D), with perhaps a narrow edge for Heck. Cortez Masto would be the first ever Latina senator. Heck, meanwhile, was viewed as Republicans’ top recruit and has tried to position himself as a moderate, while Democrats are hoping to tie him to Trump.

Now, Trump has actually seems to be staying surprisingly close to Clinton in Nevada. However, it’s a tough state to poll — in recent years, pollsters have had difficulty modeling the preferences of Hispanic voters. In any case, if Cortez Masto wins, Democrats will only need to pick up four Republican-held seats to take the chamber; if she loses, that magic number rises to five.

Where Republican incumbents are currently favored: Ohio, Florida, Missouri, Arizona, and more

Still, the good news for Democrats is that they have several potential opportunities in other states as well.

Florida and Ohio are the other two marquee Senate races taking place in presidential swing states. But in both of them, the Republican incumbents look to be in reasonably strong positions so far — though they can’t be said to be out of the woods yet, especially with Trump at the top of the ticket.

In Ohio, Sen. Rob Portman (R) seems to have done a good job heading off a challenge from former Gov. Ted Strickland (D) so far. Portman has won endorsements from several unions while portraying Strickland as a failed governor who couldn’t turn around the state’s economic troubles. Portman has consistently led recent polls, usually in the mid- to high single digits, and a conservative outside group recently canceled its ads in the state, which may suggest that some private polling also shows Portman comfortably ahead.

And in Florida, Sen. Marco Rubio (R) has led every recent poll pitting him against the likely Democratic nominee, Rep. Patrick Murphy (D), by about 5 points on average. Democrats argue that that’s a surprisingly small lead given Rubio’s advantage in name recognition, and the fact that Murphy’s been embroiled in a nasty primary against liberal firebrand Alan Grayson. But Republicans attest to confidence that Murphy is a weak candidate with a thin résumé, and hope Rubio will be able to fend him off.

In any case, Democrats will likely spend heavily against Rubio in hopes that a defeat will end his political career and remove a top threat to a potential Clinton reelection campaign in 2020.

Then Democrats think they have two more particularly tantalizing pickup opportunities in Missouri and Arizona. In the Show Me State, Democrats were thrilled that Secretary of State Jason Kander (D) — who's young, a veteran, and a formidable fundraiser — entered the race against Sen. Roy Blunt (R), a longtime mainstay in Congress whom they’re trying to portray as the consummate "Washington insider."

And in Arizona, five-term Sen. McCain (R) was recorded a few months back saying that with Trump at the top of the ticket, "this may be the race of my life," because "the Hispanic community is roused and angry in a way that I've never seen in 30 years." He faces Rep. Ann Kirkpatrick (D), whose fundraising has been strong. Both Blunt and McCain are only narrowly ahead in polls.

This isn’t the end of the list for Democrats. If the national environment deteriorates further for Republicans, other incumbents — like Sen. Chuck Grassley (R) in Iowa and Sen. Johnny Isakson (R) in Georgia — could potentially be in trouble too. But for now, these look to be their best opportunities.

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