Maria Sharapova, the highest paid female athlete in the world, has admitted to testing positive for the banned drug meldonium.

Here to explain what that means, for the tennis star and for the sport: Cindy Boren, sports reporter for The Washington Post.

Boren explained that Sharapova had received several emails warning her about the impending change in banned drugs, but apparently she either didn't see them or ignored them.

Long before Facebook or Tumblr, New York City teenagers went to YCteen magazine to publish essays about the difficult, profound things going on in their lives. 

Holly St. Lifer, the editor of YCteen Magazine, talks about the magazine's 250th issue, which features stories about gender issues.

St. Lifer is joined by three young writers:

• Jovani Hernandez, who wrote about his late mother in "Missing My Mom."

Civil rights activist and now mayoral candidate DeRay Mckesson discusses the 2016 presidential campaign and his own candidacy for the mayor of Baltimore.

DeRay hasn't endorsed a candidate in the presidential race, but Brian asked him to compare the Democratics. He said Bernie Sanders has proactively addressed a wide-ranging set of issues over the years, and economic issues come most naturally to him. "I think he is learning about racial inequity."

As for Clinton, "She has been slow to address a set of really important issues. At this point she has addressed some in a comprehensive way." DeRay recalled meeting with her last summer on behalf of Black Lives Matter, and he said he was left with "more questions than answers" after that meeting.

So how will Mckesson know how much the Black Lives Matter movement has succeeded? He says the movement is still young and has managed to fundamentally change the national conversation about race and policing, but important next steps will be coalition-building and implementing change from the inside.

Donald Trump and Bernie Sanders have something in common: they both had a pretty good night after yesterday's primaries.

Also they both talk about trade all the time, says Melinda Henneberger, which is what pushed Michigan voters to support Sanders.

Henneberger, Roll Call editor-in-chief, talks about Tuesday's primaries and caucuses in Michigan, Mississippi, Hawaii and Idaho.

Last night also highlighted Hillary Clinton's weakness with white working class men and independent voters, two groups that she'll need to win over, said Henneberger.

And who had the worst night? It would be hard to argue anybody but Marco Rubio, who fell far behind in the polls and didn't win any delegates. That's partly because of a number of bad debate performances, and also because, in Henneberger's words: "His attempt to out-Trump Trump backfired badly."

@BrianLehrer feel strongly that it is a factor Have heard both sexes say a woman shouldnt be Prez.

@BrianLehrer & we need to acknowledge it. "She's untrustworthy" is a broad statement w gender-based undertones.

@BrianLehrer How about we don't like Hilary because of her corporate ties. Sanders supporters love @SenWarren Gender for most is a non issue

@BrianLehrer It's insulting to be told that anti-Hillary is anti-woman. I am anti-secrecy, anti-war crimes, anti-corporate corruption.

@BrianLehrer Sexism isn't a factor for me it's the candidate. I also would have a problem voting for her if Sanders isn't the nominee

@clarityhaynes @BrianLehrer Thank you!! I agree, sexism is a huge factor & often a matter of subconscious bias even among millennials.

@BrianLehrer People don't trust Clinton to do what she says, but don't think Trump will act in line with what he says; odd double standard?

Lawrence Ross, writer, filmmaker, social media and consumer trends expert and the author of Blackballed: The Black and White Politics of Race on America's Campuses (St. Martin's Press, 2016), talks about the racism he finds at American colleges and universities, and in their sororities and fraternities.

Ross said for many African Americans who attend universities, outside historically black institutions, college can seem like “a four-year plan to drive black students completely crazy.” Ross highlighted the role racial microaggressions can have on making day-to-day campus life difficult for black students, especially because of a culture that is often dismissive of racially inappropriate or insensitive comments and practices.  

Jim O’Grady, WNYC features reporter, and Kai Wright, features editor at The Nation, introduce their new podcast, "There Goes the Neighborhood" that takes an in-depth look at the issues surrounding gentrification in Brooklyn.

? Hear more: The first episode of "There Goes the Neighborhood" is out! It takes place in Bed-Stuy, where 30-year resident Monica Bailey talks about the house she lost. Listen here. 

Michael Bloomberg has officially come out and said it: no, he will not take the plunge into this year's presidential elections.

Howard Wolfson, political strategist and former New York City deputy mayor who served as a counselor to former Mayor Bloomberg, talks about his decision not to enter the 2016 presidential race.

Here's one argument Bloomberg made against his own candidacy:

"As the race stands now, with Republicans in charge of both Houses, there is a good chance that my candidacy could lead to the election of Donald Trump or Senator Ted Cruz. That is not a risk I can take in good conscience."

Wolfson explained it in this way: while a Sanders-Trump-Bloomberg race would have provided a strong path to victory for Bloomberg, a Clinton-Trump-Bloomberg race would've risked an outcome where none of the candidates secured enough delegates, leaving the choice to our Republican congress.

The New York Times recently reported that Trump's anti-immigrant rhetoric is motivating legal residents to become citizens before November, just so they can cast a vote against him.

Many Mexican immigrants want to naturalize before the election to vote against Donald Trump https://t.co/6mvFGlaus5

Listeners called in to talk about where they're from, how far along in the naturalization process they are, and who they're planning to vote for in November.

You can keep the conversation going anytime on Twitter @BrianLehrer.

The tension has been escalating at Trump rallies, not only between protesters and supporters but also between protesters and Secret Service agents.

Robert Mackey, senior writer for The Intercept, talks about some recent incidents at Trump rallies, including a confrontation between a photographer and a Secret Service agent that was caught on camera and is now being investigated.

He also explained the complications of free speech when the Secret Service are involved.

And Trip Gabriel, political reporter for The New York Times who's been covering the Trump campaign, speaks from experience: He got thrown out of a campaign event once.

Janette Sadik-Khan, former NYC transportation commissioner and the author of Streetfight: Handbook for an Urban Revolution (Viking, 2016), offers a guide to accomplishing in other cities what she did in New York.

? Hear more: Janette Sadik-Khan will be in conversation with David Byrne at the Union Square Barnes and Noble on Wednesday, March 9th at 7pm. Click here for more information.

? Another chance to hear Sadik-Khan: She'll be at the Brooklyn Bowl for her book party on Thursday, March 10th at 6:45pm. Find out more here.