Season Four of Showtime’s political docuseries “The Circus” returns Sunday ahead of the 2020 primary season. National polls show the race for the Democratic nomination narrowing between former Vice President Joe Biden, Senator Elizabeth Warren and Senator Bernie Sanders. Wagner joins “CBS This Morning” to discuss the massive New York City rally Elizabeth Warren held earlier this week and what that means for the Democratic nomination. Source

Former 49ers safety Adrian Colbert could find himself in a niche role for the Seahawks very soon Source

Nurses strike after contract talks with the hospital broke down this week amid a dispute over staffing levels and pay raises Source

Emory Hunt has his finger on the pulse of Mountain West football Source

Central bank has had to inject $200 billion into the banking system this week alone, though experts say not to worry Source

The powerful storm that’s slamming Texas is now blamed for at least two deaths. Houston was inundated with more than nine inches of rain Thursday – that breaks the single-day record set in 1979 by more than two inches. Many communities devastated by Hurricane Harvey’s floodwaters just two years ago find themselves underwater again. Houston fire officials say they responded to nearly 2,000 emergency incidents. Mireya Villarreal reports. Source

de Blasio had been struggling in polling over the course of the race thus far Source

Researchers are working hard to determine the cause of more than 500 cases of lung illness affecting e-cigarette users. Eight of those people have died. Even before this outbreak, e-cigarettes divided the medical community. The American Lung Association says bluntly, “e-cigarettes are not safe.” But the American Cancer Society says they are “significantly less harmful for adults than smoking regular cigarettes.” However, the latest figures show nearly five million children use e-cigarettes. “CBS This Morning” co-host Tony Dokoupil set out to see the science for himself. Source

Eight deaths in the U.S. are now blamed on vaping, with the latest happening in Missouri. The Food and Drug Administration has revealed a criminal investigation of vaping-related illnesses. The CDC reports at least 530 confirmed and probable cases. Most of them involve vaping with THC, the psychoactive ingredient in marijuana, or both THC and nicotine. A bipartisan group in Congress is working with parents to keep teenagers away from e-cigarettes, while accusing the vaping industry of marketing to kids. Tony Dokoupil reports. Source

Dulce Maria Alavez vanished Monday from Bridgeton City Park about 30 miles south of Philadelphia Source