Roll Call’s final ranking of the most vulnerable senators doesn’t vary much from previous versions — the result of an unfavorable national climate for Democrats that has failed to improve.

On the eve of the midterm elections, Senate Democrats are staring down a hole dug by President Barack Obama’s disapproval ratings and an unforgiving map packed with red states. Retirements by a quartet of senators in Republican-leaning or swing states didn’t help, but the seats of at least four incumbents seeking re-election aren’t on much stronger ground.

It’s the reality of what could end up being a dreadful cycle for Democrats. Still, party strategists remain cautiously optimistic they can hold on to a few endangered seats, possibly even pick up a GOP open seat in Georgia and save the majority. Republicans need a net gain of six seats.

The ultimate installment of Roll Call’s 10 most vulnerable senators list features eight Democrats and two Republicans, with Democrats in the top four slots. There is a reasonable argument for any of these incumbents to be re-elected, and, indeed, there may be no more than four senators defeated. Six senators lost in the wave year of 2006, but only seven have lost in the three general elections since.

Here’s who may not be coming back this time:

1. Sen. Mark Pryor, D-Ark.

Pryor put up a strong fight against Republican Rep. Tom Cotton in a GOP-trending state that’s seen Senate campaign ads for the past 20 months. After ups and downs for both candidates, Cotton is closing strong and a favorite to win.

2. Sen. Mary L. Landrieu, D-La.

The three-term incumbent is likely headed to a Dec. 6 runoff against GOP Rep. Bill Cassidy. Both parties have already reserved millions of dollars on the airwaves for a race that will essentially reset. Still, if Republicans have won the majority or are on the brink of it, Landrieu’s chances may take a final, insurmountable hit.

3. Sen. Mark Begich, D-Alaska

To save his seat, Begich is counting on his ground game in rural and remote parts of the state, a turnout boost from a trio of ballot initiatives and criticism of Republican Dan Sullivan’s lack of Alaska roots. It may be enough, but this is still a solidly Republican state.

4. Sen. Mark Udall, D-Colo.

Both Udall and Republican Rep. Cory Gardner are leaning hard on their get-out-the-vote operations in the home stretch in this swing state. Gardner has the momentum, leading almost every poll in the past month. Democrats contend their turnout operation can help them close the gap, but with the entire state voting by mail, it’s hard to predict turnout.

5. Sen. Pat Roberts, R-Kan.

Roberts is in better shape than he was a month ago. He has pulled even with independent Greg Orman in the polls, and outside groups have helped the senator dominate the airwaves. But Roberts’ fate may still come down to whether Kansas voters can get over his lack of a permanent residence in the state he represents. If they can’t, no amount of money or star-studded stumping will keep him in the Senate.

6. Sen. Kay Hagan, D-N.C.

Republican Thom Tillis may have fought it to a tie, after narrowly trailing Hagan in polls for the past two months. This has been the most expensive Senate race this cycle, and both sides continue to pump money onto the already oversaturated airwaves.

7. Sen. Jeanne Shaheen, D-N.H.

Shaheen retains the edge against former Sen. Scott P. Brown. But Brown has gradually closed the gap, and with the winds blowing in Republicans’ favor, this race could be a nail-biter — and an early harbinger of an ominous night for Democrats.

8. Sen. Mitch McConnell, R-Ky.

Despite Democrats’ extended investment of resources in support of Alison Lundergan Grimes, who has kept the race competitive, the Senate minority leader is favored to hold on by a small, single-digit margin and — should the GOP net six seats — become majority leader.

9. Sen. Al Franken, D-Minn.

At one point, there seemed to be an opening for Republican businessman Mike McFadden to mount a real challenge to Franken. But in polls from the past two months, Franken’s lead has never shrunk below seven points, and this race has fallen off the map for Republicans.

10. Sen. Jeff Merkley, D-Ore.

Merkley leads Republican Monica Wehby by an average of 13.5 points, according to RealClearPolitics. Expect to see him in the Senate next year.

Roll Call Election Map: Race Ratings for Every Seat

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