Massachusetts Senator Elizabeth Warren ended her campaign for president on Wednesday. The decision comes after she failed to win a single state on Super Tuesday. She came in third here in Massachusetts, behind Joe Biden and Bernie Sanders. WGBH News' Adam Reilly was at Warren's announcement today. He spoke with WGBH All Things Considered Arun Rath. This transcript has been edited for clarity.

Arun Rath: So Warren made the announcement in Cambridge, where she first announced her run right at the end of 2018.

Adam Reilly: Yeah, that was her exploratory committee run, so not technically her official announcement, but for all intents and purposes, it's where she kicked off her campaign, and it's where she ended it.

Rath: What did she seem like? What was her mood like?

Reilly: Her mood was pretty upbeat. She was asked if she had any regrets about her candidacy. She said she didn't, in part because, as she put it, all these ideas that she was advocating passionately for a decade ago when she was a professor at Harvard Law School are now getting a big hearing nationally in a way they weren't before. For example, that wealth tax that she's proposed, or universal child care, things like that. So she seemed pretty positive for someone who was just marking the end or announcing the end of this massive endeavor that has failed.

Rath: There were naysayers from the beginning. Did Warren have any words for those?

Reilly: This was a really striking moment. She said that some people gave her advice when she was thinking about running for president, saying that it was a bad idea. And she said it turns out they knew what they were talking about:

"I was told at the beginning of this whole undertaking that there are two lanes — a progressive lane that Bernie Sanders is the incumbent for and a moderate lane that Joe Biden is the incumbent for," said Warren. "And there's no room for anyone else in this. I thought that wasn't right. But evidently, I was wrong."

Now, one question that answer raises is, well, what if Elizabeth Warren had tried to split the difference between Sanders and Biden in a more consistent manner? My own take, having covered her, is that she was a lot closer to Sanders ideologically than she was to Biden. But it's really easy to sit on the outside of these things and second guess, especially after someone wraps up their candidacy. It's a lot harder in practice to pull off what I'm proposing there.

Rath: It's not an original idea to say that some people are thinking that the reason people were breaking for Sanders over Warren comes down to sexism. Did did she talk about that at all?

Reilly: She was asked about the role that gender played in the arc of her campaign today, and she gave a really interesting answer. She said that it's a "trap question." That's the phrase she used. She said that if you say that sexism played a role in the reception you got, people call you a whiner, and if you say that it didn't, mass quantities of women hearing you say that sexism was not an issue say, what's she talking about? Of course it was. And Warren closed that portion of her comments by saying that she is going to have a lot more to say on this topic in the near future.

Rath: Warren hasn't made a choice yet when it comes to endorsements. Can you talk about what might be the calculus there as she's thinking between Sanders or Biden, or maybe even just keeping quiet?

Reilly: Well, let me start by telling you what she had to say today when she was asked about that, because it came up a couple of times. She said, I'm not going to do it right now. She said that she needs to take a deep breath and think about what is going to come next, and she urged her supporters to do the same when she was prompted by a reporter.

I mean, I guess one thing that she is probably going to be weighing is will it have a positive impact on Democrats as a whole if I decide to publicly back either Joe Biden or Bernie Sanders? And if it is going to be something that could have a positive effect on the Democratic candidate, ultimately in the general election, who am I going to be able to get more of a policy bang for my buck with when it comes to endorsement? You can imagine — and here I'm just kind of gaming it out — Bernie Sanders has a lot of policy proposals which are fairly similar to hers. Joe Biden doesn't have as many. So in that sense, you could make a case that she could have more to gain by coming out to back Biden, because she might pull him a little bit to the left. I don't know what's going on in her head, but I should note that while she said she wasn't going to endorse right now, she did not say, I will definitely endorse down the road. So that's another possibility worth considering — maybe she won't back anyone at all.