ANNOUNCER: This is the Washington Week Webcast Extra.

GWEN IFILL: Hello, I'm Gwen Ifill.

Welcome to the Washington Week Webcast Extra, where we pick up where we left off in the weekly broadcast.

Joining me around the table, Robert Costa of The Washington Post, Christi Parsons of Tribune Newspapers, Pete Williams of NBC News, and Jeff Zeleny of CNN.

One of the more unusual features of this campaign season?

The defeated candidate who will not quit.

Bernie Sanders has hinted at concession several times, meeting with the president, meeting with Secretary Clinton, and most recently speaking to his supporters online.

But when it comes to officially suspending his campaign, no dice.

So what does he have to lose and what does he have to gain by staying in?

JEFF ZELENY: Well, the main thing he has to gain by staying in officially is that it keeps his movement alive, and at least it delays the reaction of really annoying, agitating, turning off his supporters.

If he would come out and say I now endorse Hillary Clinton, they would think he's a sellout.

And I've heard that word over and over and over from some Bernie or bust people, the movement that wants him to sort of go all out.

So he's signaled in every way possible that he is, you know, going - he wants to defeat Donald Trump, that he'll be helpful, but he cannot say the words "I endorse Hillary Clinton" because he would lose a lot of his movement.

He wants to keep this going, for what we don't know.

I mean, there will be, you know, just - he is sort of the leader of the progressive movement for now, but he knows that that is fleeting.

But I was a very - GWEN IFILL: So he has nothing to lose, either?

JEFF ZELENY: Nothing to lose.

He has nothing to lose at all.

And the Clinton campaign is not all that worked up about it.

He's not causing trouble anymore.

He is, you know, insisting he will help defeat Donald Trump.

The question is, can he actually turn his supporters toward Hillary Clinton, or can he not?

And that is an open question, I think.

The anger among his core supporters toward her is so intense, he has stirred up something so much, and you wonder why he can get over it.

Well, there's a couple reasons.

One, he's a professional politician, very much an insider.

He's campaigned as though he's this outside figure, but when he went back to his office in the - in the Dirksen Senate Office Building last week, he was back at home.

There's one reason for Bernie Sanders to fall in line.

That's the word "chairman."

If Democrats win control of the Senate next year, which they hope to do and he'll campaign for that, he will likely be a chairman, perhaps of the Budget Committee, so - GWEN IFILL: But, boy, if Hillary Clinton in 2008 had decided to drop - not drop out and not be the good Girl Scout, boy - JEFF ZELENY: Sure, as some of her supporters wanted her to do, remember?

GWEN IFILL: Yeah.

ROBERT COSTA: It's different.

I was with Senator Sanders on the night of the Los Angeles primary, and he took forever to make this decision to go to Santa Monica to have his rally.

But you just got the sense in the hotel lobby that he was not a party man.

He's not really thinking about the party.

GWEN IFILL: He just joined the party.

ROBERT COSTA: He just joined the party.

And when he was - when he walked into that hangar in Santa Monica and he said the struggle continues, that place exploded.

And they weren't there for Democratic reasons, they were there because they were progressives.

GWEN IFILL: Somebody reported that Jane Sanders said to him that night, hey, you still got 'em.

ROBERT COSTA: She whispered it in his ear.

You can see the clip: they're still with you.

GWEN IFILL: Yeah, yeah, they're still with you, exactly.

OK, let's go on to another former candidate, but one who actually dropped out of the race: Marco Rubio.

He is back in the headlines again because it looks like, after all the terrible, awful things he said about the United States Senate, he might be running again.

ROBERT COSTA: He is one of the most absentee senators.

He doesn't seem to like the institution, but - GWEN IFILL: Next to Bernie Sanders.

ROBERT COSTA: But it looks like he's going to likely announce, based on my reporting, sometime next week that he's running.

You had David Jolly, the congressman, on Friday decide - PETE WILLIAMS: For the Senate, right.

ROBERT COSTA: For the Senate.

GWEN IFILL: For the Senate.

ROBERT COSTA: For the Senate.

He probably wants to run in 2020, 2024 for the presidency.

GWEN IFILL: (Inaudible) - yeah.

ROBERT COSTA: But he's going to likely run for the Senate.

Based on what I heard on Capitol Hill, he recognizes that if he does want to run in 2020 or 2024, he can't just be someone who gives corporate speeches and the occasional think tank panel, he's got to be in the arena.

CHRISTI PARSONS: But how does he overcome all that we've heard over the campaign season about how he was never in the Senate chamber?

ROBERT COSTA: He's only 45 years old.

His narrative is still being written.

GWEN IFILL: Here's the best part about this story.

David Jolly, the congressman who was running - his friend who was running for the seat who dropped out, is now running for his old seat against Charlie Crist, who never goes away in Florida politics.

So we have another reason to go to Florida, as if it ever lacks reasons.

OK, now, Christi, I'm going to go to you because I want to talk to you a little bit about the president in campaign mode.

This is his last campaign, you know, his daughter's graduating, going away, he is crying all the time.

CHRISTI PARSONS: Openly weeping.

(Laughter.)

GWEN IFILL: Exactly.

So how much is he champing at the bit to get out of the White House and be on the campaign trail?

CHRISTI PARSONS: Oh, he really is.

He's dying to get out of the White House.

And in fact, his staff was really having to hold him back in advance of the Bernie Sanders sort of sliding out of the race.

He wanted to get out there, and you could see it in his face.

He's got nothing to lose anymore.

He feels so unbound, and he also just feels like the stakes are really high for his - for his legacy, and he's really dying to get out there.

GWEN IFILL: But I wonder if getting out there also means getting out there on policy.

We talked about the gun control - the gun issues, and other policy issues that he's now building a legacy around, I wonder if that's what he is hoping that Hillary Clinton will do.

I mean, he's almost like openly agreeing that this is going to be a third Obama term, which nobody would have ever said out loud a short time ago.

CHRISTI PARSONS: Well, isn't that what it looked like, too, in that joint or the tandem speeches that Hillary and Obama gave this week, when people were doing the montage and you could see they were saying the same thing?

GWEN IFILL: The same words.

CHRISTI PARSONS: It was almost like I was waiting for their images to blur together.

It looked like a campaign ad, and I do think that's part of what's going on.

To me it's interesting how he's talking about guns because I'm not sure it's such an easy slam dunk for Hillary and for the candidates down the ballot just because, you know, the more you talk about taking people's guns, the more I feel like it plays into the Trump story in a way that could maybe - GWEN IFILL: Which base are you energizing when you do that?

ROBERT COSTA: You got that right.

CHRISTI PARSONS: Could be animating a base that's very ambivalent toward Trump.

GWEN IFILL: Pete, you got another big week coming up, and that's the end of the Supreme Court term.

And we are waiting for how many of these - PETE WILLIAMS: Thirteen decisions left.

We've actually got this week and next week.

GWEN IFILL: Only small issues like health care, affirmative action, abortion.

What else do you have?

PETE WILLIAMS: Well, we have the president's immigration policy.

That's probably the biggie because that would make the biggest difference.

We have affirmative action, which the Court could decide in a way that slices it very narrowly.

This is the program from the University of Texas at Austin, and it's unusual because under state law it accepts the top 10 percent of every - roughly the top 10 percent of every high school graduating class.

And the Court could say, you know, it's different there, so that's our answer on affirmative action.

I can't imagine they're going to say you can't have affirmative action in college admissions.

I can't imagine they're going to say whatever you do is fine.

So I have a hunch it'll be sliced fairly narrowly.

And then another case from Texas is - all three of the big cases are from Texas.

You've got the Texas lawsuit over immigration, you've got the affirmative action, and then you've got the Texas abortion law that says doctors have to have admitting privileges at hospitals or the clinics have to be built to ambulatory care standards.

GWEN IFILL: You've got just this week to get them done.

How many decision days?

PETE WILLIAMS: No, we have - we have this coming Monday, probably yet another day, and then also the last week in June.

GWEN IFILL: OK, and you still have a - not a split Court, but you still only have eight justices.

PETE WILLIAMS: Only eight justices.

GWEN IFILL: Will that affect the outcomes of any of the big, big cases?

PETE WILLIAMS: Yes, except on affirmative action.

Elena Kagan has already sat that one out, so we're down to seven, so we're not going to have a tie on that one for sure.

And the Court - you know, the Court is giving every sign - and we've heard this sort of among the Court watchers, the Court insiders as well - that they're doing everything they can to try to find common ground and avoid a tie.

GWEN IFILL: OK. Well, we'll see if that actually happens.

We've heard that common ground term before.

Thank you, everybody.

Stay online all week long for the latest developments on these and other stories from the best reporters in Washington, our panelists.

That's, of course, at PBS.org/WashingtonWeek.

And that's where you'll also find my take on what the president said about guns behind the scenes in Indiana two weeks before the Orlando attack.

And we'll see you next time on the Washington Week Webcast Extra.