In the 2018 Senate elections, Democrats will have serious advantages — an unpopular President Trump, the historic trend of voters punishing the party in power — and one huge obstacle: 10 Senate Democrats are running for reelection in states that Trump won in the 2016 presidential election. You’re gonna hear about that a lot.

That hurdle is the big reason why, though the current Senate has 51 Republicans and 49 Democrats and therefore Democrats would need to flip only two seats to reclaim control of the chamber, Democrats are still the underdogs in the 2018 battle for the Senate.

And this week, with Justice Anthony Kennedy’s retirement and the prospect of another Donald Trump-appointed judge on the Supreme Court being confirmed by the Senate this fall, the stakes just became much more vivid.

In some of these states, like West Virginia, where Sen. Joe Manchin might have the toughest race of his life, Trump won with 70 percent of the vote two years ago and remains very popular with voters. Indiana’s Joe Donnelly, Missouri’s Claire McCaskill, Montana’s Jon Tester, and North Dakota’s Heidi Heitkamp are other Senate Democrats with difficult terrain. Others — Ohio’s Sherrod Brown and Florida’s Bill Nelson, for example — are running in more traditional swing states. Wisconsin’s Tammy Baldwin is vying for reelection on the site of one of Trump’s most surprising triumphs.

The 2018 midterms will be the collision of two opposing forces: incumbent senators hoping to benefit from the national anti-Trump mood but in states where Trump remains relatively popular. Every race comes with its own quirks and scandals.

It’s a lot to keep track of. So we thought we’d give you a rapid-fire breakdown of the elections where control of the Senate will be determined. Who’s running, what does the state look like, what’s the narrative of the campaign? Come on this journey with us, ranked from the toughest to easiest races for Deomcrats.

The “Trump Country” tier: Democrats in real danger in states that love Trump

West Virginia: Joe Manchin vs. Patrick Morrisey

Who is the Senate Democrat? Joe Manchin, elected to the Senate in 2010. He was governor and secretary of state before that. He’s pretty moderate or even conservative by Democratic standards, though he, like everybody else on this list, voted against Obamacare repeal and the Republican tax bill.

Who is the Republican? Attorney General Patrick Morrisey prevailed in the May 8 primary, beating Don Blankenship, a former coal baron who ran a company found to be violating federal safety regulations when a mining accident killed 29 people, and avoiding a disaster for DC Republicans. Morrisey ran on his record as attorney general, where he sued the Obama administration repeatedly over environmental regulations and other federal rules, positioning himself as the conservative outsider in the race.

How much does the state like Trump? Trump won with 68 percent of the vote, his highest margin in the country. His approval rating is still 61 percent, highest of any state, per Gallup, the source for the rest of this list’s numbers. Manchin’s approval rating, meanwhile, is so-so: 43 percent approve; 44 percent disapprove, per Morning Consult, also our go-to source.

What’s interesting about this race, anyway? Manchin has a strong history with the state, though his brand of centrism might risk alienating actual progressives in the year of the Resistance. “There’s a very strong anti-establishment sentiment in West Virginia, and there’s also an ‘it can’t get any worse’ sentiment,” Patrick Hickey, a political science professor at West Virginia University, told me. “We’re just trying to shake it up.”

Do we know who’s going to win? Nope! Nonpartisan post-primary polling has given Manchin leads of 7 points and 13 points over Morrisey, but you can except that to tighten as Republican money pours into the race. The folks at Cook Political Report say it’s a toss-up.

North Dakota: Heidi Heitkamp and the indecisive Kevin Cramer

Who is the Senate Democrat? Heidi Heitkamp, elected in 2012, former state attorney general. Moderate. Just voted to confirm Trump’s chosen Secretary of State Mike Pompeo, for example.

Who are the Republicans? Rep. Kevin Cramer, at least the last time I looked. Cramer was going to run, then he wasn’t, but now he is definitely running after a little bit of jostling from the Washington GOP establishment. They wanted a good candidate against Heitkamp; this is a top Republican target.

How much does the state like Trump? Trump in 2016: 63 percent. Trump approval now: 57 percent (second in the nation). Heitkamp approval: 47 percent, 39 percent disapproval. Pretty good!

What’s interesting about this race, anyway? Now that Cramer is in, this will be a close race. He’s allied himself closely with Trump, particularly on key state issues like energy. Heitkamp does her best to cut an independent image, though expect her votes on Obamacare repeal and the tax bill to be used against her. She is pretty popular, nonetheless, and remember that North Dakota is one of the redder states that still expanded Medicaid under the ACA.

Trump himself gave this race some attention after Kennedy’s retirement, predicting Heitkamp would oppose his next SCOTUS nominee (even though she had voted for Neil Gorsuch).

Do we know who’s going to win? There are just two polls of this race: Heitkamp led by 3 points back in February, and Cramer was up 4 points this month. It’s a toss-up.

Indiana: Joe Donnelly doesn’t want you to know he’s a Democrat

Who is the Senate Democrat? Joe Donnelly, elected to the Senate in 2012. Former representative. Possible changing-clothes-while-driving wizard.

Who are the Republicans? State legislator Mike Braun topped Reps. Todd Rokita and Luke Messer in the May 8 primary.

How much does the state like Trump? This is Vice President Mike Pence’s home state, remember. Trump won with 56 percent of the vote in 2016. He’s underwater now, though: 44 percent approve, 51 percent disapprove. Donnelly is sitting at 42 percent approval and 32 percent disapproval.

What’s interesting about this race, anyway? Donnelly’s campaign announcements are really wonderful. A few recent samples from my inbox:

Joe Donnelly, Indiana Republicans launch ‘Republicans for Joe’ in Indianapolis

Joe Donnelly worked with Republicans to deliver bipartisan successes to stabilize nation’s health care system after McConnell sabotage

Joe Donnelly worked with Republicans to pass crucial ‘Right to Try’ legislation

This is a man who will remind you he is a Democrat only when absolutely necessary, which is probably smart in the Hoosier State. Meanwhile, Braun just beat two House Republicans in the latest display of the electorate’s anti-establishment sentiments. It’ll be an interesting campaign.

Do we know who’s going to win? The only post-primary poll shows Braun with a 1-point lead over Donnelly. Another race for the toss-up pile.

Missouri: Claire McCaskill, Josh Hawley, and Eric Greitens star in another wild race here

Who is the Senate Democrat? Claire McCaskill, elected in 2006. Todd Akin slayer. Cancer survivor.

Who is the Republican? State Attorney General Josh Hawley, presumptively, but uh, we’ll get back to that.

How much does the state like Trump? Trump got 56 percent in 2016. But these days, he is more divisive: 47 percent approval, 48 percent disapproval. McCaskill has 39 percent approval and 44 percent disapproval.

What’s interesting about this race, anyway? Missouri’s Republican governor, Eric Greitens, was ensnared in several different scandals — one in which he’s accused of sexual misconduct, another involving a veterans charity — before he was forced to resign in May. Republicans in the state desperately wanted him out, none more so than Hawley, who was doing everything he could to remove Greitens. McCaskill is vulnerable, as evidenced by her approval rating, but a state GOP tainted by scandal could be a big boost to her chances.

Do we know who’s going to win? It’s probably gonna be close. McCaskill is eking out a 1.7-point lead on average right now, per RealClear Politics. I can’t see the future.

The “unexpected toss-up” tier: Florida

Florida: Bill Nelson versus Rick Scott will be the most expensive race of 2018

Who is the Senate Democrat? Bill Nelson. Elected way back in 2000. Space traveler.

Who are the Republicans? Republican Gov. Rick Scott, who is a pretty awkward human being but a pretty popular governor nevertheless. Notably stood up to the National Rifle Association after the Parkland high school shooting. Even Democrats give him credit for that. Scott is also very, very, very rich and willing to spend his own money on campaigns.

How much does the state like Trump? Trump eked out a 49-47 win in 2016. These days, he has 41 percent approval and 53 percent disapproval. Yeesh! Nelson is looking much stronger: 47 percent approval and 29 percent disapproval.

What’s interesting about this race, anyway? I’m not going to lie: These guys are really boring. Even their ostensible allies in the state say so. This race is all about money: Scott has a lot of it, he has nothing else to spend it on, and Nelson will have to keep up. There are some interesting twists, such as the political residue from Parkland and Puerto Ricans relocating here after Hurricane Maria. But cash rules everything around Miami.

Do we know who’s going to win? As long as Nelson isn’t dramatically outspent, he’s probably the narrow favorite. But Democrats will need some dough to make sure Scott doesn’t get the upper hand and the margin for error isn’t big: Right now, Scott actually has a two-point advantage, on average, in the polling.

The “pulling away” tier: Democrats are looking safer and safer in a few races

Montana: Jon Tester is somehow the overwhelming favorite

Who is the Senate Democrat? Jon Tester. Elected in 2006. Capitol’s best haircut. He’s pretty moderate (see this banking bill), but he’s been more willing than some of the names above him to confront Trump.

Who are the Republicans? Maryland accent-haver Matt Rosendale. First elected to Montana’s state legislature in 2010. Republicans have done a pretty good job, overall, recruiting high-quality candidates for these competitive races, but I’m sorry, nobody is excited about Matt Rosendale, the state auditor with, I repeat, a notable Maryland accent.

How much does the state like Trump? Trump in 2016: 56 percent. Trump now: 52 percent. Tester: 56 percent approval, 33 percent disapproval.

What’s interesting about this race, anyway? Did you see Tester’s approval rating? Montanans like this guy. The main wild card is how much Trump himself intervenes — especially after Tester helped sink the president’s Veterans Affair nominee, Ronny Jackson. The president is already going after Tester pretty hard.

Secret Service has just informed me that Senator Jon Tester’s statements on Admiral Jackson are not true. There were no such findings. A horrible thing that we in D.C. must live with, just like phony Russian Collusion. Tester should lose race in Montana. Very dishonest and sick! — Donald J. Trump (@realDonaldTrump) April 28, 2018

Do we know who’s going to win? Tester, probably. Cook ranks this race as Likely D, which is saying a lot. Earlier this month, Gravis showed Tester up by 8 points over Rosendale.

Wisconsin: Tammy Baldwin is really running against Scott Walker

Who is the Senate Democrat? Tammy Baldwin. Elected in 2012. Preexisting conditions advocate. Medicare-for-all endorser.

Who are the Republicans? Former Democrat Kevin Nicholson, whose parents have given money to Baldwin, and state Sen. Leah Vukmir are the frontrunners. She’s a conservative with closer ties to Gov. Scott Walker’s in-state establishment. He used to be a Democrat but has a compelling personal bio as a former enlisted Marine. Primary isn’t till August 14.

How much does the state like Trump? Another narrow Trump 2016 win, with 47 percent. Not so Midwestern nice for the president now: 41 percent approval and 55 percent disapproval. Badgers seem lukewarm on Baldwin: 40 percent approval, 42 percent disapproval.

What’s interesting about this race, anyway? The headliner in Wisconsin 2018 elections is Walker, bane of the state’s progressives. As Republicans and Democrats in the state told me, the more Baldwin can contrast herself with the divisive governor, the better off she’ll probably be. She’s the last statewide elected Democrat standing. Republicans want such an unabashed progressive out for that reason. There is a lot of Meaning in this race.

Do we know who’s going to win? Baldwin, I think? Cook says this is Likely D. A recent Marquette University poll found Baldwin up by at least 9 over her potential challengers. But gambling, in general, is not a healthy habit.

Ohio: everybody seems to think Sherrod Brown is going to win

Who is the Senate Democrat? Sherrod Brown. Elected in 2006. Perennial presidential or vice presidential dark horse.

Who is the Republican? Rep. Jim Renacci edged out Cleveland businessman Mike Gibbons, who had no political experience and a lot of money, in the May 8 primary.

How much does the state like Trump? The nation’s best state voted for Trump with 51 percent of the vote in 2016. Trump now: 45 percent approval, 50 percent disapproval. Brown is popular: 46 percent approval and 29 percent disapproval.

What’s interesting about this race, anyway? We’ve got to speed this up. Brown has a strong in-state brand and is a real progressive who’s willing to credit Trump on things like tariffs; Renacci is not a very inspiring candidate facing scrutiny of his history as a DC lobbyist.

Do we know who’s going to win? Brown, probably. An Ohio Republican predicted to me that Brown would win by 8 to 10 points. Right now, according to RCP, he’s leading Renacci in the polls by an average of 15 freaking points.

The “never in doubt” tier: Democrats were always going to win these

Pennsylvania: Bob Casey probably doesn’t have too much to worry about

Who is the Senate Democrat? Bob Casey, US senator since the 2006 election, believe it or not. Very nice guy. Unassuming. His dad was the governor a few decades ago.

Who is the Republican? US Rep. Lou Barletta, the establishment’s favored son in this race, won the May 15 primary.

How much does the state like Trump? Trump’s signature 2016 win, with 48 percent of the vote. He’s fallen off, though: 42 percent approval, 53 percent disapproval. Casey is in good shape: 42 percent approval, 32 percent disapproval.

What’s interesting about this race, anyway? You might have heard about Conor Lamb, House special election heartthrob. Pennsylvania is probably a real swing state now, especially for the White House, but 2018 is a very good environment for Democrats. See: Democrat Lamb winning in a district that Trump carried by 20 points.

Do we know who’s going to win? The most recent polls have Bob up by at least 15 points. 15! So Casey, barring a big surprise. Can’t remember one of those in recent campaigns.

Michigan: if anybody on this list is safe, it’s Debbie Stabenow

Who is the Senate Democrat? Debbie Stabenow, who has been in the Senate a loooong time. Elected in 2000! Medicare buy-in-for-people-over-55 sponsor.

Who are the Republicans? I actually had to look this one up. Not Kid Rock. Not Fred Upton, longtime Congress member. Businessman and veteran John James and other businessman/Yale and Harvard economist Sandy Pensler are considered the Republican frontrunners. Historic preservationist Bob Carr is also running. You learn something every day. The primary is August 7.

How much does the state like Trump? Trump won with 47 percent in 2016. I don’t know where those voters went, because now he has just 40 percent approval and 55 percent disapproval. Stabenow is faring better: 42 percent approval, 38 percent disapproval.

What’s interesting about this race, anyway? This is a long post. Nobody outside Michigan is really paying attention to this race for a reason. Debbie should be fine.

Do we know who’s going to win? Stabenow. Probably. The only poll we have puts her up 21 points. Cook puts this in the Likely D camp. So do I.