For the first time this cycle, the senators on the list of most vulnerable incumbents have changed.

Operatives in both parties agree Democratic Sens. Sherrod Brown of Ohio and Bob Casey of Pennsylvania are favored to win re-election even though they are running in states that backed President Donald Trump in 2016. Texas Republican Ted Cruz and New Jersey Democrat Robert Menendez replace them on the list.

Red-state Democrats still dominate, with North Dakota Sen. Heidi Heitkamp remaining in the top spot. Nevada Republican Dean Heller is still the second-most vulnerable incumbent with the wind at Democrats’ backs this midterm.

Strategists on both sides say it’s too early to know how the battle over Trump’s Supreme Court pick Brett Kavanaugh could shake up these Senate races. His nomination hangs in the balance after Christine Blasey Ford’s testimony last week that he sexually assaulted her when they were in high school.

This list is based on conversations with strategists from both sides of the aisle, polling, and the race ratings from Inside Elections with Nathan L. Gonzales. We look solely at vulnerable incumbents and do not include open seats that are likely to flip.

Watch: What Surprised Roll Call’s Politics Team This Midterm Season (So Far)

1. Sen. Heidi Heitkamp, D-N.D.

Heitkamp remains at the top of the list since she still faces headwinds of running in a ruby-red state against its at-large congressman, Republican Kevin Cramer. Both are well-liked in the state. Democrats have countered that Heitkamp, the only statewide-elected official from her party, has a fundraising advantage and a strong personal background, and note that she could capitalize on issues such as trade and health care. Trump won the state by 36 points in 2016.

Race rating:Tilts Republican

2. Sen. Dean Heller, R-Nev.

Heller is still in trouble given the national environment and strong fundraising by the Democratic nominee, freshman Rep. Jacky Rosen. Heller is the only GOP incumbent running in a state Clinton won in 2016. (She carried it by 2 points.) Both parties expect the race to be close, given that Rosen had to build her name recognition. Democrats maintain they have an effective line of attack against Heller by highlighting his back-and-forth over the GOP health care overhaul.

Race rating:Toss-up

3. Sen. Claire McCaskill, D-Mo.

McCaskill stays put at No. 3, running in a state Trump carried by 19 points. She has been stressing health care, prompting the GOP nominee, state Attorney General Josh Hawley, to air a TV ad saying he supports protections for people with pre-existing conditions. Hawley, a former Supreme Court clerk, is hoping the battle over the high court vacancy could energize Republican voters. McCaskill said prior to Ford’s testimony that she would oppose Kavanaugh because of his views on campaign finance. Polling has shown a tight race here, and McCaskill has to peel off some independent and conservative-leaning voters while driving up Democratic turnout.

Race rating:Toss-up

4. Sen. Joe Donnelly, D-Ind.

GOP nominee Mike Braun may not be living up to expectations here, but given that Trump carried the state by nearly 20 points, Donnelly remains in the same spot he was a month ago. Donnelly may have to contend with his previously announced opposition to Kavanaugh, but it’s too soon to tell whether that will excite Republican voters who have been underwhelmed by Braun.

Race rating:Toss-up

5. Sen. Bill Nelson, D-Fla.

Both parties acknowledge that Nelson is in slightly better shape than he was a month ago, when GOP Gov. Rick Scott largely had the airwaves to himself. Democrats are encouraged that despite Scott’s heavy spending over the summer, the Republican wasn’t able to put the race away. Even so, Nelson remains at No. 5. The demographics here are more favorable to Democrats than most other states on this list, but Scott and his millions are still formidable.

Race rating: Toss-up

6. Sen. Jon Tester, D-Mont.

Montana’s two-term senator switches places with his colleague from West Virginia, which is largely a reflection of Manchin’s strength. Tester also has a strong personal brand against an out-of-state transplant, state Auditor Matt Rosendale. Democrats are weaponizing that contrast. But recent GOP polling has shown a tightening race in a state Trump won by 21 points. Republicans’ best path to victory has always been nationalizing the contest, and they’ve done that by dispatching Trump multiple times.

Race rating:Tilts Democratic

7. Sen. Joe Manchin III, D-W. Va.

Eleven months ago, back when his opponent was still unknown, Manchin was No. 4 on this list. Despite running in a state Trump won by 42 points, he’s gradually slid down, dropping two spots since Attorney General Patrick Morrisey won the GOP nomination in May. Many Republican attacks on Manchin have been mitigated by Morrisey’s own vulnerabilities. Democrats, meanwhile, have made the race about pre-existing conditions, accusing Morrisey of being behind the effort to take away protections because he signed on to a lawsuit against the 2010 health care law.

Race rating:Tilts Democratic

8. Sen. Tammy Baldwin, D-Wis.

Trump only carried Wisconsin by less than 1 point, but Baldwin has supported more liberal proposals such as “Medicare for All” legislation, so she keeps her spot at No. 8. She faces state Sen. Leah Vukmir, who won a costly GOP primary in August. Baldwin’s fundraising advantage has allowed her to air several TV ads, but plenty of outside money has also poured into the state. While Republicans tout their strong state party infrastructure, Wisconsin Democrats have also proved this year that they are energized.

Race rating:Leans Democratic

9. Sen. Ted Cruz, R-Texas

Cruz is new to the list, mainly because both parties agree that Brown and Casey’s races have not picked up. Meanwhile, Cruz’s Democratic opponent, Rep. Beto O’Rourke, has raked in enormous amounts of campaign cash, which has helped him hit the airwaves in the expensive state. While polling has shown that Cruz has a real race on his hands, O’Rourke still faces an uphill battle in a Republican state, which Trump carried by 9 points.

Race rating:Likely Republican

10. Sen. Robert Menendez, D-N.J.

The New Jersey Democrat’s first appearance on this list is also more a reflection of Republicans’ fading chances in Trump states such as Ohio and Pennsylvania than it is about his potential electoral demise. In a Democratic state with a proven tolerance for scandal, voters aren’t likely to ditch him for Bob Hugin, a self-funding pharmaceutical executive who served as chairman of Trump’s state campaign. But Hugin’s spending is making the race competitive — even prompting the Democratic Senatorial Campaign Committee to reserve time here. Menendez may be ahead, but more than one poll has shown him in an uncomfortable spot for an incumbent — and at the very least, in a tighter race than Brown or Casey at this point.

Race rating:Solid Democratic