Democratic front-runners Joe Biden and Elizabeth Warren will face off for the first time in a presidential debate Thursday night. Ten of the 2020 candidates will take the stage in Houston for the third Democratic presidential debate, which will highlight competing visions for the party’s direction. Two new CBS News contributors – Marco Rubio’s former campaign manager Terry Sullivan, and Hillary Clinton’s former campaign manager Robby Mook – join “CBS This Morning” to discuss the upcoming debate. Source

A look back at what we’ve been covering on “CBS This Morning.” Source

The White House is moving to curb the vaping epidemic in America that’s linked to at least six recent deaths. A new initiative would ban most flavored e-cigarettes, allowing only tobacco flavor. Cases of possible vaping- related illnesses have been reported in at least 36 states, including Hawaii, Idaho, and Washington, which just reported their first cases this week. Dr. David Agus joins “CBS This Morning” to discuss why we still don’t know the full health impact of e-cigarettes and the challenges of regulating them. Source

The New York Times is reporting that just weeks before winning horse racing’s Triple Crown last year, Justify failed a drug test. According to the Times, Justify tested positive for a banned substance about a month before the Kentucky Derby. But instead of disqualifying the horse, which could have kept it out of the Derby, the state’s horse racing board took more than a month to confirm the results. Source

The push for more aggressive gun reforms comes in the wake of recent shootings in Texas and Ohio Source

A recently filed lawsuit alleges that a fertility clinic in New Jersey gave a woman sperm from a man who was not her husband. The couple is seeking monetary damages and information on their daughter’s biological father. But the family’s attorney said that regardless of the outcome of the suit, the family’s lives have been “devastated.” Meg Oliver reports. Source

A CBS News investigation uncovered a new Medicare fraud that could potentially cost taxpayers hundreds of millions of dollars. Recruiters are showing up at senior events promoting a genetic test they claim is completely paid for by Medicare. They promise the test will reveal information about their cancer risk. But the results often do not come in, and the bills can be in the thousands. Jim Axelrod reports. Source

A fertility clinic in New Jersey is being ordered to turn over a list of sperm donors after a white couple gave birth to an Asian baby. A recently filed lawsuit alleges Kristina Koedderich was given sperm from a man who was not her husband, and that the man passed on a genetic disorder. The couple is seeking monetary damages and information on their daughter’s biological father. Meg Oliver reports. Source

President Trump says a ban on most flavored vaping products is the right response to what health officials call an “epidemic” of e-cigarette use by teenagers. A recent jump in illnesses linked to vaping has grabbed the attention of lawmakers, regulators, and parents, including the president and first lady. But CBS News has learned any real crackdown is likely a long way off. It will take weeks for the FDA to release its final rule — and even then, companies have time to respond. Paula Reid reports. Source

Market research shows 22 million adults in the U.S. use e-cigarettes. On Wednesday, President Trump called for a ban on most flavored vaping products. But some consumers, who vape instead of smoking traditional cigarettes, say they deserve the right to choose flavored products because they’re legally old enough. Meanwhile, some business owners worry that Trump’s suggested ban will cripple sales. Janet Shamlian reports. Source