A significant part of the federal government is shut down indefinitely because President Trump is insisting on $5 billion for a border wall (or steel fence) and Democrats are saying no. But Trump's "wall" fixation actually began as little more than "a memory trick for an undisciplined candidate," Julie Hirschfeld Davis and Peter Baker report at The New York Times.

As Mr. Trump began exploring a presidential run in 2014, his political advisers landed on the idea of a border wall as a mnemonic device of sorts, a way to make sure their candidate — who hated reading from a script but loved boasting about himself and his talents as a builder — would remember to talk about getting tough on immigration. [The New York Times]

Trump embraced the idea once he saw the enthusiastic response his promise of a Mexico-funded border wall received among conservative audiences. "He's very obsessed about carrying out his campaign promises — I think to a degree that's unhealthy — but that's important to him, and that's not a bad thing," Trump friend Christopher Ruddy, CEO of Newsmax, tells the Times. White House counselor Kellyanne Conway says Trump is "focused on the wall" because "he thinks you need a very robust physical barrier at the border that you can't climb over, slide under, drive through or walk around." Her husband, George Conway, had a different interpretation:

Many of Trump's fellow immigration hardliners view his wall as a counterproductive, minor-to-insignificant part of broader restrictions on legal and illegal immigration. You can read more about the genesis of Trump's wall, and its critics on both sides of the immigration debate, at The New York Times. Peter Weber

The Trump administration held a record 69,550 migrant children in U.S. government custody in fiscal 2019, up 42 percent from the previous year, and it detained the children for longer periods of time, The Associated Press and PBS Frontline reported Tuesday. The number of migrant children detained away from their parents also outpaced any other nation in the world, according to United Nations researchers. Canada, for instance, detained 155 separated children in 2018, and Britain sheltered 42 migrant children in 2017; Australia detained 2,000 children during a maritime surge in 2013.

The U.S. government has acknowledged that detaining children can lead to long-term physical and emotional trauma. "Some of these migrant children who were in government custody this year have already been deported," AP reports. "Some have reunited with family in the U.S., where they're trying to go to school and piece back together their lives. About 4,000 are still in government custody, some in large, impersonal shelters."

"Early experiences are literally built into our brains and bodies," says Dr. Jack Shonkoff at Harvard's Center on the Developing Child. He warned Congress earlier this year that detaining kids away from their parents or primary caregivers rewires their brains. The American Academy of Pediatrics said in the September issue of journal Pediatrics that migrant children who are detained "face almost universal traumatic histories." The longer the detention and the younger the detainees, the greater chance of serious trauma.

When President Trump took office, the Department of Health and Human Services was caring for about 2,700 children, most of whom were reunited with parents or relatives in about a month, AP reports. In June, HHS had more than 13,000 children in custody and they stayed in detention for about two months. On Nov. 5, a federal judge ordered the government to immediately provide mental health treatment and screening to detained migrant families, ruling that there is sufficient evidence government policy "caused severe mental trauma to parents and their children" and U.S. government officials were "aware of the risks associated with family separation when they implemented it." Peter Weber

The team behind Sonic the Hedgehog worked as fast as possible to tweak the character's look after fan backlash, and it seems their efforts paid off.

Paramount Pictures on Tuesday released the new trailer for the film based on the video game series, and it reveals a redesign of the central character. When the original trailer dropped in April, Sonic's design was met with widespread mockery, with fans complaining about everything from his disturbing human-looking teeth to his strangely buff legs. The movie originally would have hit theaters last week, but after the backlash, it was delayed three months, with director Jeff Fowler saying the team was "taking a little more time to make Sonic just right."

Now, we see the fruits of their labor, and in the new trailer, Sonic looks far more like a cartoon and closer to the video game series, with his eyes being larger and mouth looking less freakishly human.

Immediately, the trailer was met with a warm reception among fans, who flooded it with likes on YouTube and voiced their approval of the look. Of course, whether the film itself will be any good is an entirely different question, so we'll find out whether all this was worth it when the film hits theaters on Feb. 14. Brendan Morrow

Disney+ has officially become part of your streaming world.

The brand new Disney streaming service officially launched in the U.S. on Tuesday morning, debuting with the first episode of the live-action Star Wars TV series The Mandalorian. As promised, the premiere featured a bombshell reveal for the franchise that sparked quite a bit of Twitter buzz. Other originals available at launch include the new live-action Lady and the Tramp movie and High School Musical: The Musical: The Series.

The Disney+ library also boasts tons of films from throughout the studio's history, including its animated classics, plus Star Wars and Marvel films, although not everything is available immediately; some movies, like Star Wars: The Last Jedi, are tied up on Netflix for now.

Also available on Disney+ is Avengers: Endgame, which became the highest-grossing film of all time earlier this year and originally wasn't expected to debut on the service until December. Films have a separate tab on the service for bonus features, and Endgame's section includes a previously-unreleased deleted scene in which Katherine Langford plays an older version of Tony Stark's daughter in a vision sequence.

The Disney+ launch comes less than two weeks after Apple also entered the streaming market with its own streaming service, Apple TV+, which costs $4.99 per month. Disney CEO Bob Iger has described Disney+ as a "bet on the future of this business," clearly having realized that streaming ain't no passing craze. Brendan Morrow

The Supreme Court will hear 80 minutes of oral arguments Tuesday from defenders and opponents of the Deferred Action for Childhood Arrivals (DACA) program, which shields about 660,000 immigrants who grew up in the U.S. from deportation. Texas and 12 other states are challenging the legality of the program, instituted by former President Barack Obama in 2012, but lower courts in California, New York, and Washington, D.C., have blocked President Trump's plans to end the program, citing Trump's violations of the Administrative Procedure Act.

Until the Supreme Court hands down its decision, the young immigrants — or DREAMers — already in the program can renew their 2-year work and residency permits but new DREAMers can't enroll in the program. One of the lawyers defending DACA at the Supreme Court is a DREAMer from Washington State. The lead advocate for the program on Tuesday will be famed litigator Theodore Olson, joined also by California's solicitor general. Peter Weber

Former Massachusetts Gov. Deval Patrick (D) is preparing to enter the crowded Democratic presidential race as soon as this week, two people with knowledge of his plans told multiple news organizations Monday. He will presumably decide by Friday, the filing deadline for the New Hampshire primary. Patrick, 63, served as governor from 2007 to 2015. Democratic voters say they are pleased with the current crop of Democratic candidates, but some wealthy donors and Wall Street executives have expressed concerns about Sen. Elizabeth Warren's (D-Mass.) rise and the stalled prospects of more moderate former Vice President Joe Biden. Patrick is one of the candidates they have been trying to lure into the race; another candidate, former New York City Mayor Michael Bloomberg, made his own late forays into the race last last week.

Patrick brings a strong résumé and compelling biography, but he's also trying to extricate himself from Bain Capital, the private equity firm co-founded by Mitt Romney, and has some family baggage. When he announced he wouldn't run last December, Patrick cited "the cruelty of our elections process" and how it would "splash back" on people he loves. Patrick's reconsideration "is coming from Wall Street," a source tells Politico. "They're terrified of Warren. And these guys would help Biden. But they've been in a room with him up close and they have doubts. ... Deval wants this. He regrets not having done it. His wife was ill. But since then, she has gotten better. But the field has gotten worse." Peter Weber

Former President Jimmy Carter was admitted to Emory University Hospital in Atlanta on Monday evening to prepare for a Tuesday morning operation to "relieve pressure on his brain, caused by bleeding due to his recent falls," the Carter Center said in a statement. Carter, who recently turned 95, is the oldest living ex-president ever. He has fallen at least three times this year, including one tumble that required a hip replacement in the spring and a pelvis fracture on Oct. 21. In 2015, Carter was diagnosed with brain cancer and then declared cancer-free.

In between health scares, Carter had been building houses with Habitat for Humanity and teaching Sunday school at Maranatha Baptist Church in his hometown of Plains, Georgia. "We just need the whole country to be in prayer for him," Carter's pastor, Rev. Tony Lowden, told The Associated Press. Peter Weber