Senate Democrats have one enormous advantage even as they face one of the most difficult political terrains in recent memory: They are not the party that controls the White House.

A new analysis of election results over the past 10 midterm cycles underlines that since 1978, incumbents of the party out of power, even in states the president carried in the previous election, are overwhelmingly likely to win another six-year term.

This is true, the analysis states, even in states where the president cruised to reelection.

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In states that went for the president by more than 10 percentage points, the other party’s senator has won reelection in the following midterm more than 90 percent of the time.

Over that period, 43 senators have run for reelection in states the other party’s president won by more than 10 percentage points. Only four — Max Cleland (D-Ga.) in 2002, Al D’Amato (R-N.Y.) in 1998, Howard Cannon (D-Nev.) in 1982 and Edward Brooke (R-Mass.) in 1978 — lost their reelection bids.

Such statistics are of crucial interest given this year’s Senate map, in which 10 Democratic incumbents will run for reelection in states President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE won in 2016.

“Every midterm, it’s always good to be the party out of the White House,” said Bruce Mehlman, a Republican lobbyist who analyzed the 333 Senate races that have taken place since 1978 as part of a widely-read quarterly political update to clients.

Five Democratic senators are running for reelection in states Trump won by more than 10 points: Sens. Joe Donnelly Joseph (Joe) Simon DonnellyHarris faces pivotal moment with Supreme Court battle Trump meets with potential Supreme Court pick Amy Coney Barrett at White House Names to watch as Trump picks Ginsburg replacement on Supreme Court MORE (Ind.), Claire McCaskill Claire Conner McCaskillMomentum growing among Republicans for Supreme Court vote before Election Day Democratic-linked group runs ads in Kansas GOP Senate primary Trump mocked for low attendance at rally MORE (Mo.) and Heidi Heitkamp Mary (Heidi) Kathryn HeitkampHarris faces pivotal moment with Supreme Court battle Centrists, progressives rally around Harris pick for VP 70 former senators propose bipartisan caucus for incumbents MORE (N.D.) are among the most vulnerable members seeking reelection. Sens. Joe Manchin Joseph (Joe) ManchinManchin defends Supreme Court candidate Barrett: 'It's awful to bring in religion' The Hill's Morning Report - Sponsored by Facebook - Trump, GOP allies prepare for SCOTUS nomination this week Trump meets with potential Supreme Court pick Amy Coney Barrett at White House MORE (W.Va.) and Jon Tester Jonathan (Jon) TesterDemocrats shoot down talk of expanding Supreme Court Pence seeks to boost Daines in critical Montana Senate race This World Suicide Prevention Day, let's recommit to protecting the lives of our veterans MORE (Mont.) are seen as safer bets, though their wins are by no means assured.

Five other Democrats are running for reelection in states Trump won by fewer than 10 points: Sens. Tammy Baldwin Tammy Suzanne BaldwinSenators introduce bipartisan bill to mandate digital apps disclose country of origin Keep teachers in the classroom Cher raised million for Biden campaign at LGBTQ-themed fundraiser MORE (D-Wis.), Sherrod Brown Sherrod Campbell BrownHarris faces pivotal moment with Supreme Court battle Remote work poses state tax challenges Senate Democrats release report alleging Trump admin undermined fair housing policies MORE (Ohio), Bob Casey Robert (Bob) Patrick CaseySecond GOP senator to quarantine after exposure to coronavirus GAO report finds brokers offered false info on coverage for pre-existing conditions Catholic group launches .7M campaign against Biden targeting swing-state voters MORE Jr. (Pa.), Bill Nelson Clarence (Bill) William NelsonDemocrats sound alarm on possible election chaos Trump, facing trouble in Florida, goes all in NASA names DC headquarters after agency's first Black female engineer Mary W. Jackson MORE (Fla.) and Debbie Stabenow Deborah (Debbie) Ann StabenowOVERNIGHT ENERGY: Trump rollbacks could add 1.8 billion tons of greenhouse gas emissions over 15 years: analysis | Intensifying natural disasters do little to move needle on climate efforts | Experts warn wildfire smoke could worsen COVID-19 GAO report finds brokers offered false info on coverage for pre-existing conditions Democrats back away from quick reversal of Trump tax cuts MORE (Mich.). Of those five, only Nelson has a top-tier challenger, in Florida Gov. Rick Scott (R).

If history holds, all five of those senators will be back for another six-year term. In the last 10 midterms, no senator seeking reelection from a state the other party’s president won by fewer than 10 percentage points has lost.

Incumbents from the party out of power have a better chance of winning reelection than incumbents from the same party that holds the White House, Mehlman found.

Just about half of members of a president’s party win reelection in states the president did not carry. Over the last 40 years, the incumbent of a president’s party has won reelection in 14 of 27 attempts in a state the president did not carry.

This year, only one Republican — Sen. Dean Heller Dean Arthur HellerOn The Trail: Democrats plan to hammer Trump on Social Security, Medicare Lobbying World Democrats spend big to put Senate in play MORE (R-Nev.) — falls into that category. But Trump lost Nevada to Hillary Clinton Hillary Diane Rodham ClintonDemocratic groups using Bloomberg money to launch M in Spanish language ads in Florida The Hill's Campaign Report: Presidential polls tighten weeks out from Election Day More than 50 Latino faith leaders endorse Biden MORE by just 2.5 percentage points, and the incumbent senator has won nearly 69 percent of the time if their party’s president lost by such a narrow margin.

The president’s party has held 80 percent of open seats in states he carried by more than 10 points over the last 10 midterms, but just 31 percent of seats that the president carried by less than a 10-point margin. This year, that means Republicans have a strong chance to retain Sen. Bob Corker Robert (Bob) Phillips CorkerHas Congress captured Russia policy? Tennessee primary battle turns nasty for Republicans Cheney clashes with Trump MORE’s (R-Tenn.) seat, but they have a far weaker chance of holding on to Sen. Jeff Flake Jeffrey (Jeff) Lane FlakeHow fast population growth made Arizona a swing state Jeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Republican former Michigan governor says he's voting for Biden MORE’s (R-Ariz.) seat in a state Trump carried by only 4 percentage points.

“It’s better to be a Democratic incumbent in a state Trump won by more than 10 than a Republican open seat candidate in a state Trump won by less than 10,” Mehlman said.