There are things presidential candidates like to talk about, and there are things they'd prefer not to. (For us, more or less everything on the trail falls into the first category.)

WHAT HILLARY CLINTON WOULD LIKE TO TALK ABOUT TODAY: Party unity, and Donald Trump. 

"I look forward to coming together to unify our party to stop Donald Trump and move our country forward because there’s much more that unites us than divides us," Clinton told a labor crowd in Las Vegas today. "...We are going up against a candidate who will say anything, do anything to take us backward on every issue and value we care about. Donald Trump is an urgent threat to our rights and to our country."

The attack today most likely to get under Trump's skin was aimed straight at his wallet: Maybe, Clinton said, he's not so rich after all.

"Hillary Clinton upped the pressure on Donald Trump to release his tax returns on Thursday, suggesting that he is trying to hide unflattering revelations about his finances," reported Abby Phillip.

"'Either he’s paying no taxes or he’s paying very little,' Clinton said. 'The only way to find out which it is is for him to release.'

"'Either he’s as wealthy as he claims or maybe he’s not, the only way to find out is for him to release.'"

WHAT HILLARY CLINTON DOESN'T WANT TO TALK ABOUT: The issue at the top of her inbox today: the emails.

. (Photo by Melina Mara/The Washington Post)

"Voters may have concerns about her use of a private email system as secretary of state but will consider 'the full picture of what I have to offer' as she runs for president, Hillary Clinton said Thursday,"  reported Anne Gearan.

"The Democratic presidential front-runner spoke one day after a State Department report concluded that she had gone around department procedures in setting up and using a private email system that operated outside government security and record-keeping controls.

"In a short television interview in Las Vegas, Clinton repeated her long-standing explanation that previous secretaries of state also had used private accounts.

"'This report makes clear that personal email use was the practice for other secretaries of state. And I know that because it is well known, it’s pointed out in the report. But it was still a mistake,' Clinton said. 'And as I’ve said many times, if I could go back, I would do it differently. I know people have concerns about this.'"

Those commentssaid Chris Cillizza, "showed, yet again, that Clinton will stick to her story on her email server even if the increasingly indisputable facts get in the way. 

"...There remains zero allegation of criminal wrongdoing by Clinton in all of this. And what she continues to say about why she set up the email server and whether she was allowed to has pieces of truth in it. But, it isn't totally true. And she has to know that."

WHAT DONALD TRUMP WOULD LIKE TO TALK ABOUT (besides Hillary Clinton's emails):

It's unofficially official. REUTERS/Jonathan Ernst

According to the Associated Press delegate count, Trump officially gained his 1,237th today, giving him the majority he needs to claim the Republican presidential nomination in July.

His team is happy too, they say. We say: we haven't seen this much giddy excitement over a finale since the Twitter reaction to the last five minutes of How I Met Your Mother.

(In Trump's photo of his own private celebration, he appears just as thrilled)

WHAT DONALD TRUMP SAYS HE DOESN'T WANT TO TALK ABOUT: "Donald Trump said Thursday that unless any new information surfaces, the 1993 death of then-White House deputy counsel Vincent W. Foster Jr. should not be discussed on the presidential campaign trail," reported Jenna Johnson.

"Foster was a close friend of Bill and Hillary Clinton and several investigations at the time of his death concluded that it was a suicide, although conspiracy theories continue to circulate. Trump, the presumed GOP nominee, said Tuesday in an interview with The Washington Post that Foster 'knew everything that was going on, and then all of a sudden he committed suicide.' Trump said then that although he doesn't know much about the case, he had heard that some people believe 'it was absolutely a murder.'

"Foster’s sister Sheila Foster Anthony has criticized Trump for “cynically, crassly and recklessly” insinuating that her brother had been murdered and said that it is 'beyond contempt that a politician would use a family tragedy to further his candidacy.'

"'How wrong. How irresponsible. How cruel,' Foster wrote in an op-ed that was published on The Post’s website Thursday."

WHAT WE'RE PRETTY SURE DONALD TRUMP DOESN'T WANT TO TALK ABOUT (besides yesterday's campaign staff drama) BUT BERNIE SANDERS DOES: That hypothetical Trump-Sanders debate.

Here's a relatable real-world metaphor for you: You probably have a friend who has asked you to hang out, even though they aren't really the sort of friend with whom you'd like to hang out. The only possible response to such a request is, of course: "Sure, let's hang out sometime."

You are focused on that second half of the sentence: the nebulous time element — that moment which, for you, is likely to remain forever in the future tense. Your friend will inevitably focus, like a laser, on the first half. And they will email you, and text, and call, until the two of you somehow wind up in the same room at the same time, on purpose, or you start screening. For the purposes of this metaphor, Bernie Sanders today was your friend. And Donald Trump was you.

Last night, when Jimmy Kimmel passed along a Sanders request for a debate ahead of the June 7 California primary, Donald Trump said he was on board — if the price was right. (Today, he set that price at $10-15 million that might be donated to groups that handle "women's health issues.") Ever since the Kimmel interview, Bernie Sanders and his team have released a steady stream of tweets, press releases, and comments cheering the news. "I am very excited about it," the senator told a California crowd today.

Trump and his team have appeared...slightly less thrilled, spending the same period appending asterisks to that original reply. There have been no tweets. There have been no statements. This does not mean they've ruled it out! The important thing to remember here, Trump's team says, is that he's happy to debate "whether it happens or not"; right now, they're just "waiting to see if it happens." In other words: don't call them, Sen. Sanders. They'll call you.

(If you're already nostalgic for what might have been, but may not ever be: here's what a Trump-Sanders debate might have sounded like)

WHAT BERNIE SANDERS WOULD RATHER NOT TALK ABOUT: To start with: Kentucky, where the Sanders-requested recanvass of the narrow Clinton primary victory returned the same outcome

Not only was a Kentucky win a long shot — even a best-case scenario would have delivered minimal returns: perhaps a single delegate, in a race where Sanders trails by several hundred. "So why bother?" asks Philip Bump. Here's why, maybe:

—"...[Sanders] still claims to be able to win, but he usually focuses on an argument that his campaign should head to the convention with as many delegates as possible, in order to best twist arms on policy fights."

—"His campaign has also embraced the idea that they've been unsuccessful in part because the system is working against them -- particularly after the Nevada fight." (Kentucky secretary of state Alison Lundergan Grimes, who backs Clinton, herself has been looped into that.) So Sanders very publicly took on the system.

—"Sanders has been loathe to call Kentucky a loss. Part of his argument in the last few weeks of the contest has been that he has robust momentum, winning state after state." If he could have somehow pulled out an official win in Kentucky, that argument would have been more easily preserved.

"You might say, then, that Sanders notched a victory simply by making this request. His supporters who are looking for him to battle the establishment get to see him battle the establishment. He can talk about how he's fighting for every delegate (though that one delegate almost certainly would never make any difference). And he gets to sow doubt about the 'real' winner of the Kentucky primary," says Bump.

"It's the small-ball approach to winning the presidency. I'd call it the 'moneyball' approach, after the once-popular idea that working the numbers could make up for a financial disadvantage. But Sanders isn't at a disadvantage in money. Just votes." Which the Kentucky recanvass didn't deliver.

There's another problem with the momentum narrative Sanders would probably rather not dwell on: the fact that the primary season will end with a contest that is likely to deliver a healthy Clinton win.

#CHART TIME! And now, the most depressing graphic we've seen this week. Enjoy. (Here's the full breakdown.)

TRAIL MIX:

At the Jinhua Partytime Latex Art and Crafts Factory, a Halloween and party supply business that produces thousands of rubber and plastic masks of everyone from Osama Bin Laden to Spiderman, masks of Donald Trump and Democratic frontrunner Hillary Clinton faces are being churned out. Sales of the two expected presidential candidates are at about half a million each but the factory management believes Trump will eventually run out the winner. "Even though the sales are more or less the same, I think in 2016 this mask will completely sell out," said factory manager Jacky Chen, indicating a Trump mask. REUTERS/Aly Song 

—Trump talked general election strategy today, saying he plans to focus on 15 states where "it could go either way." And that he considers California one of those swing states. (In case you're wondering: as of today, there has yet to be a poll that shows Clinton with less than a double-digit lead over Trump in a hypothetical fall faceoff) 

—Since this week has been all about the 90s: Rmember that episode of Friends where Joey couldn't go home for Thanksgiving because his photo was featured in a public service ad promoting venereal disease awareness? If you do: you, like us, may have been oddly intrigued by rumors that the same sort of thing had happened this week — except with Stock Photo Guy simultaneously starring in both a syphilis PSA and a presidential campaign ad. If that had happened, it would have felt a bit like a weird validation of our decision to waste what probably amounts to several days of our lives watching Friends re-runs. We hate to act as a dream destroyer here, but: it did not happen. Sorry.

—Hillary Clinton called today for Democratic unity. Sanders campaign manager Jeff Weaver told MSNBC that unity would be "much easier" to achieve if DNC chair Debbie Wasserman-Schultz stepped aside. (Debbie Wasserman-Schultz has, of course, shown no inclination to step aside.) The question: could the DNC chair's exit wind up being the Vermont senator's ultimatum to Clinton?

—Bernie Sanders is winning the street art primary. (This contest does not award any delegates.)

—When you are a reporter, sometimes politicians send you press releases from the future. For the record: If people are going to send us detailed info on events that haven't happened yet, just once we'd like them to include the Powerball.

—This month Donald Trump has been against teleprompters, in favor of them, and against them. Today: he used a teleprompter (mostly) to deliver a policy speech, so we think he's back on the Teleprompter Train. All this is to say: Typically, the Trump campaign does not release prepared remarks, because there are no prepared remarks. Today, there were. So if you want to know exactly what Donald Trump had to say about energy policy, you can find it here. And if you want more context, here's a Post analysis.

—The latest GOP primary contender to complete an about-face on Trump: Marco Rubio. "Reversing months of comments to the contrary, Sen. Marco Rubio (R-Fla.) now says he plans to attend the Republican National Convention and will release his delegates to vote for the presumed party nominee, Donald Trump," reported Ed O'Keefe.

"Rubio once warned that nominating Trump would 'fracture the Republican Party' and faulted the business magnate for stoking violence at his rallies. But in a CNN interview on Thursday, Rubio said he's attending the GOP convention in Cleveland because 'I want to be helpful. I don't want to be harmful, because I don't want Hillary Clinton to be president.'"

Which brings us to today's primary season #TBT: here's Rubio, telling reporters ahead of the Florida primary that "Donald Trump is not a leader."

—Trump no longer refers to Rubio as Little Marco (often.) But the nicknames continue: the presumptive Republican nominee has been calling Sen. Elizabeth Warren (D-Mass.) — who has raised the volume on her Trump attacks this week — "Pocahontas," saying that he does not believe Warren's assertion years ago that she has Native American heritage.

Today, Trump was in North Dakota — a state that is home to a significant population of Native Americans, one of whom told Trump his new nickname for Warren was offensive. He apologized. (Then used it again.) He also said that Warren had a "big mouth." With all that in mind, it's worth noting that, much like Trump, the Massachusetts senator has a keyboard and a penchant for tweetstorms. She's also fundraising off the feud. In other words: this isn't over.

—Trump and his top strategist — who has spent much of the past few weeks suggesting in interviews that Trump might be...flexible on several of his core talking points — seem to have different views on where the candidate stands on a Muslim travel ban. 

—Trump may be the symbolic head of the GOP now, but he doesn't own it, says Dan Balz, because the man who has everything doesn't actually seem to want that thing. "It’s been called a hostile takeover of the Republican Party, but there’s little that has happened since Donald Trump became the GOP’s presumptive nominee to suggest he wants anything to do with the party. He’s borrowing the brand for his own purposes..."

—House speaker Paul Ryan definitely does not want an election-year fight over LGBT rights. Paul Ryan is currently facing an election-year fight over LGBT rights.

—Donald Trump, call your office: It is still too early to look at the topline numbers for general election matchups. It's not too early to use those same surveys to gauge some fundamentals and trends of the race. Last week, Quinnipiac state polls brought some good — or at least, not at all bad! — swing state news for Donald Trump. This week's Bloomberg/Purple State strategies surveys, on the other hand, came accompanied by the pundit equivalent of sirens and flashing red lights. The bottom line: if you're a white working class voter in the Midwest, get ready to see a whole lot more Donald Trump.

—Allow us a moment to kvell: Stuart Rothenberg — perhaps the single best analyst of congressional campaign trends anywhere — is now going to be delivering that analysis to The Washington Post. We haven't been this happy since they resurrected Arrested Development.

—"21 YouTube songs called Trump Train, Ranked" (Here's one of them):

—On the trail today:

—The Trump effect? (This seems new. For Clinton, anyway. She also phoned in to MSNBC.)

—More #TBT: Donald Trump's campaign confirmed today that he will appear at the Rolling Thunder rally in DC this weekend. Today, Sarah Palin posted a photo and reminisced on Facebook about the weekend exactly five years ago when she did the same: "I'll never forget the luscious smell of that fuel and that leather, and the beautiful roar of 100,000 engines - music to my ears!"

YOUR DAILY TRAIL PIT STOP: Today, political Twitter was dazzled by a report that Journey was scheduled to play Cleveland at the tail end of the Republican National Convention. (The RNC denied any role in the booking.) No matter who's responsible, it would be the perfect convention week show, since the band is responsible for what may be the ultimate underdog campaign theme. Here it is.