A new CBS News Battleground Tracker poll shows a tight race in Iowa, with Joe Biden, Bernie Sanders, Pete Buttigieg and Elizabeth Warren all within the margin of error of each other. Antjuan Seawright, a CBSN political contributor and Democratic strategist; Eugene Scott, a political reporter for the Washington Post; and Larry Sabato, director of the University of Virginia’s Center for Politics, spoke to CBSN’s Tanya Rivero about the state of the 2020 presidential race. Source

Washington’s National Zoo is saying goodbye to Bei Bei, the last of its beloved giant panda cubs. This could be the end of an era, as Bei Bei heads to China. Chip Reid explains. Source

Beauty company Coty is buying a 51% stake in Kylie Jenner’s cosmetics business for $600 million. The deal, which values the young entrepreneur’s namesake beauty brand at $1.2 billion, will enable “global expansion and entry into new beauty categories,” the companies said in announcing the deal Monday. Source

Hundreds of protesters are trapped in a tense standoff with riot police in Hong Kong, hours after violence erupted in the streets. Overnight, police in armored vehicles clashed with students hurling gasoline bombs. Ramy Inocencio reports from Hong Kong. Source

Chick-fil-A is planning to change its charitable donations in the new year as the fast-food chain tries to avoid the spotlight that came with its history of financing evangelical groups that opposed LGBTQ rights, including same-sex marriage. CBSN Los Angeles reports. Source

It’s estimated around 1 million coronary stents are implanted in patients in the U.S. every year Source

Here’s a look at the top stories making headlines on the “CBS Evening News with Norah O’Donnell.” Source

President Trump surprised his own White House staff by tweeting that he is considering submitting written testimony in the impeachment inquiry. It comes as Democrats are now investigating whether the president lied the last time he submitted answers in writing. Ben Tracy reports. Source

The impeachment hearings are about to enter a rapid-fire round of nine witnesses in just three days. On Tuesday, Congress will hear from three people who listened in on the phone call that prompted the investigation. Nancy Cordes reports. Source

Close to 2 million Americans will receive stents to open clogged arteries. But that could change with the release of a new study. Dr. Tara Narula joins the “CBS Evening News” to explain. Source