With less than three weeks until Election Day, Democrats have managed to hang on to a narrow path to take back the Senate majority for the first time since 2014.

But key races along that path appear to be narrowing even further in Republicans' favor after the Senate confirmed Brett M. Kavanaugh to the Supreme Court, a move that could boost Republican turnout in these conservative states.

Democrats argue that these races are not necessarily tightening because of Kavanaugh but because more voters are paying attention. They say they always expected these races to be within a couple of points. Democrats do still have a good shot in many of these races, even in states President Trump won by up to 40 points. But they will need a near-perfect run of the ultracompetitive top 10 races below to do win back the Senate.

Here are the 10 most competitive Senate races of the 2018 election cycle. We have ranked them from least likely to flip parties (10) to most likely (1) .

10. Wisconsin (Democratic held), previous ranking 9: The reelection of Sen. Tammy Baldwin as the only statewide Democrat in Wisconsin looks more likely by the week. Three polls since the August primary show that GOP state Sen. Leah Vukmir hasn’t come within eight points of Baldwin. Baldwin looks to be a beneficiary of voters in the Midwest souring on Republicans two years after helping elect Trump. But this isn’t over yet. Republicans are hoping that a more competitive race to reelect Gov. Scott Walker (R) will rally voters for Vukmir.

9. Tennessee (open seat being vacated by a Republican), previous ranking 10: It’s a testament to Democrats' strength this cycle that they look more likely to pick up a Senate seat in Tennessee than Republicans do in Wisconsin. Polls are all over the place, with a recent New York Times-Siena poll showing Republican Rep. Marsha Blackburn’s lead over Democratic former governor Phil Bredesen jumping to 14 points. But Bredesen’s campaign put out a memo this week claiming the race is tied. Operatives on both sides say this race is competitive, though Republicans are slightly more optimistic they will hang onto retiring GOP Sen. Bob Corker’s seat. Democrats will almost certainly need to win this seat to take back the majority.

8. West Virginia (Democratic held), no ranking change: On paper, this is one of the most winnable seats for Republicans. Trump won the state by more than 40 points in 2016 and remains popular there. But is it slipping away from them? Sen. Joe Manchin III (D-W.Va.) may have saved his political career when he became the only Democrat to cross party lines and vote for Kavanaugh to get on the Supreme Court. A RealClearPolitics average of a handful of polls since August gives Manchin a 9.4-point lead. But Republicans aren’t counting out West Virginia Attorney General Patrick Morrisey. A Republican poll released after the Kavanaugh vote is buoying their hopes by showing the race is a dead heat. The danger for Morrisey is if Republican voters simply don’t show up now that the Kavanaugh fight is over.

7. Montana (Democratic held), no ranking change: If Manchin is the toughest red-state Democrat for Republicans to unseat, Sen. Jon Tester (D) is probably the second-toughest. Like Manchin, he has a strong brand back home, and Montana voters march to the beat of their own drum, electing Democrats and Republicans statewide in a single election. Tester is also outraising and outspending his opponent, state auditor Matt Rosendale, in the final days. And yet Republicans are feeling better about this race. There are signs that Republican and conservative-leaning voters will vote with their party, especially as Donald Trump Jr. makes frequent visits to the state. And GOP outside groups may come to Rosendale’s rescue. Public polling shows the race within the margin of error leaning slightly toward Tester, while some private polling shows it a dead heat.

6. Florida (Democratic held), no ranking change: It’s not clear what, if any, effect Republican Gov. Rick Scott’s handling of the deadly Hurricane Michael that made landfall in the Panhandle last week will have on his Senate race to unseat Sen. Bill Nelson (D). Despite Scott’s personal wealth to pour into this race, it has remained tied for months or showing Nelson leading within the margin of error. Democrats are calculating that high turnout of the kind seen in the primary and earlier special elections will put Nelson over the top. Republicans remain confident in Scott — and his millions. Like the competitive governor’s race in this state, it’s going to be a toss-up until someone wins by a percentage point or two.

5. Arizona (open seat being vacated by a Republican), no ranking change: This is another race in which the Democrats' Senate majority could rise or fall. And the race to replace retiring Sen. Jeff Flake (R) is going to be a battle to the end. Rep. Kyrsten Sinema (D) is trying to be the first statewide Democrat elected in Arizona since the George W. Bush years. And she’s got a good shot; she has led in seven of the last eight public polls. Her opponent is the skilled Rep. Martha McSally (R), a former fighter pilot who survived a chaotic primary and is cozying up to Trump to turn out the Republicans' base. Most polls show this race within the margin of error, which is a good sign for Democrats. This will be a tug-and-pull between enthusiasm on the left and the conservative underpinnings of the state.

4. Missouri (Democratic held), previous ranking 3: The final four Senate races have been ordered and reordered a number of ways because they’re all so close. Right now, polls in Missouri teeter between showing Sen. Claire McCaskill (D) with a slight lead or her opponent, Attorney General Josh Hawley, with a slight lead, or the race tied. This race is very tough to predict. Democratic operatives argue that McCaskill has a path to victory by drumming up support in majority-minority areas then hoping independents lean her way. Like Tester in Montana, McCaskill has raised tens of millions over the past three months and is outspending her opponent in the final days. Hawley is also now campaigning that he supports insurance companies covering preexisting conditions, a notable shift in rhetoric.

3. Indiana (Democratic held), previous ranking 4: We flipped Indiana and Missouri, because it’s possible that Democratic Sen. Joe Donnelly’s vote against Kavanaugh is more of a liability for him in this conservative state, which Trump won by 19 points in 2016. Still, Donnelly has been impressively hanging on against businessman Mike Braun. The sparse public polling in the state averages out to giving Donnelly a slight lead. As in West Virginia, Donnelly’s path to victory includes hoping that Republican voters don’t show up to the polls in large numbers.

2. Nevada (Republican held), previous ranking 1: After months of being The Fix’s most vulnerable senator in 2018, Sen. Dean Heller (R) gets a slight break. He is the Republicans' most vulnerable senator running for reelection by far, and his reelection in a state that voted for Hillary Clinton in 2016 is far from guaranteed. But Heller slightly leads his opponent, Democratic Rep. Jacky Rosen, in three of the last four polls. Like Republicans in these other tight races, Heller has leaned his reelection on Trump, who has come to the state to campaign for him. Will that be enough in a blue-trending state?

1. North Dakota (Democratic held), previous ranking 2: Republican operatives have been saying all along that Sen. Heidi Heitkamp (D) is the likeliest red-state Democratic senator to lose her seat in 2018. And now The Fix agrees. Even before she voted against Kavanaugh, polls were trending in favor of her Republican opponent, Rep. Kevin Cramer. Her campaign argues that it has polls showing her performing well in all the key areas of the state she needs to win. And Heitkamp remains well-liked in the state. She has run a relatively smooth campaign ― save for a political blunder at the last minute when her campaign shared a letter of 125 North Dakota women opposing Kavanaugh without their permission, in the process outing some survivors of sexual abuse and misidentifying others who aren’t survivors. Heitkamp apologized. In the end, the demographics of this state, which Trump won by 36 points, may be too challenging for Heitkamp to overcome.