Another twist comes on “The Undoing” (HBO, 9 p.m.). 

Two days before the election is a turning point for both “The Circus: Inside the Wildest Political Show on Earth” (Showtime, 8 p.m) and “Our Cartoon President” (Showtime, 8:30 p.m.). 

The new series “Killer in Question” (Investigation Discovery, 9 p.m.) looks at lingering questions after a murder case is closed.

Another new true crime series begins, “Dying to Be Famous: The Ryan Singleton Mystery” (Bounce, 9 p.m.), about the death of the aspiring model. 

Sunday Night Football has Dallas at Philadelphia (NBC, 8:20 p.m.). Earlier games include Pittsburgh at Baltimore (CBS, 1 p.m.), Minnesota at Green Bay (Fox, 1 p.m.) and New Orleans at Chicago (Fox, 4:25 p.m.).

More encouragement to vote comes from the special “Race in America: Our Vote Counts” (Bravo, E!, 10 p.m.). 

It’s Valentine’s Day on “I Love a Mama’s Boy” (TLC, 10 p.m.).

But it is of course Christmas elsewhere with “On the 12th Date of Christmas” (Hallmark, 8 p.m.) and “The Christmas Aunt” (Lifetime, 8 p.m.).

And a second season of “Holiday Wars” (food, 8 p.m.) begins, hosted by Raven-Symone.

On “The Trouble with Maggie Cole” (PBS, 8 p.m.), Peter is jittery from the press attention. 

Josto makes a bold move on “Fargo” (FX, 10 p.m.). 

“The Good Lord Bird” (Showtime, 10 p.m.), finally lands at Harper’s Ferry. 

Who would kill to be valedictorian? The characters in the made-for-TV thriller “Killer Competition” (Lifetime Movie Network, 8 p.m.). 

There’s a shutdown, too, on “Alaska: The Last Frontier” (Discovery, 8 p.m.). 

“The Spanish Princess” (Starz, 8 p.m.) faces the plague in London. 

High school is no fun on “The Walking Dead: World Beyond” (AMC, 10:14 p.m.). 

The situation gets worse on “COBRA” (PBS, 10 p.m., check local listings). 

Xander and Jett seek to grab Ralen out of the intergalactic fight club on “Pandora” (CW, 8 p.m.).

On “The Real Housewives of Potomac” (Bravo, 9 p.m.), Monique files a counterclaim. 

John investigates a death written off as an accident on “Fear the Walking Dead” (AMC, 9 p.m.). 

Turner Classic Movies has a Nancy Kwan double feature with “Flower Drum Song” (8 p.m.) and “Tamahine” (10 p.m.). The silent movie at midnight is “Behind the Door” (12:15 a.m.), followed by two German films from the 1970s,  “The Lost Honor of Katharina Blum” (2 a.m.) and “Coup De Grace” (4 a.m.).

Auto racing includes the Emilia Romagna Grand Prix (ESPN2, 7 a.m.), the Xfinity 500 (NBC, 2 p.m.) and the NHRA Nationals: Las Vegas (Fox Sports 1, 4 p.m.). 

Sunday Talk

ABC: Biden adviser Anita Dunn, Trump adviser Jason Miller. CBS: Republican chair Ronna McDaniel, Rep. Val Demings. NBC: Pennsylvania Secretary of Commonwealth Kathy Boockvar of Stanford Law School. CNN: Dunn, Pete Buttigieg, Ohio Gov. Mike DeWine, Michigan Gov. Gretchen Whitmer, Pennsylvania Gov. Tony Evers, Sen. Rick Scott. Fox News: Trump adviser Corey Lewandowski, Sen. Amy Klobuchar.