Donald Trump's ability to claim the Republican nomination could lie in the hands of roughly 200 people -- the delegates set to arrive at the convention unbound to any candidate, free to back whoever they choose.

"If Trump arrives at the July convention in Cleveland just shy of the 1,237 delegates required to secure the nomination outright, these unbound delegates could decide to push him over the top — or force a contested convention with successive rounds of balloting," reports Philip Rucker.

"'It’s the wildcatter of delegate selection,' said Ed Brookover, a senior adviser to Trump, who drew an analogy to risk-taking oilmen who drill in unexplored land.

"The three remaining candidates are identifying these delegates, researching their proclivities and beginning to cajole them. The law surrounding them is so unclear that Trump could conceivably fly them to Florida for a weekend of luxuriating at Mar-a-Lago, his gold-adorned and palm-lined private club — where, naturally, they could be subjected to personal lobbying to support Trump.

"Brookover did not rule out the Trump campaign entertaining delegates at one of Trump’s properties or paying for their travel costs to Cleveland. But he added: 'You certainly can’t offer anything which would be considered a bribe. We can’t give them $100,000.'

(This should work.)

"...After being outmaneuvered on several early delegate plays by Sen. Ted Cruz of Texas, his main rival, Trump is getting up to speed on the complicated process. On Thursday, he announced that power to oversee all activities related to the convention and delegates activities would be consolidated under Paul Manafort, a newly hired adviser."

That learning curve will need to be a sharp one. The fact that Ted Cruz's campaign has been preparing for this stage of the race for more than a year was painfully apparent to Team Trump in Colorado today.

"Ted Cruz picked up at least nine more delegates from Colorado on Friday in his quest to topple Donald Trump in the race for the Republican presidential nomination," reported Ed O'Keefe. 

"The Texas senator earned the delegates during a series of chaotic, but spirited meetings held by Colorado Republicans in packed hotel banquet rooms here at the base of the Rocky Mountains. The proceedings continue through the evening ahead of a Republican state convention on Saturday that will finalize a slate of 37 delegates to the Republican National Convention in Cleveland in July." 

As of late Friday, Cruz had picked up at least 18 delegates in the state so far this week, with 19 more still to be decided. No other candidate had any. 

"Colorado, home to one of the most chaotic state Republican parties in the nation, is one of six states or territories that decided not to hold a traditional caucus or primary to pick its presidential preference. Instead, the state party launched a months-long selection process.

"...White flyers asked convention-goers from the 5th Congressional District to vote for a Trump-backed slate that included Charles Prignano. His last name was misspelled.

"'It is the most disorganized campaign I've ever seen,' he said."

Sure, the news may sound bad for Trump. But the reality may be...even worse than it sounds, says Philip Bump.

"...Trump — as has happened so often in the past — got out-organized.

"It’s unfair to pin this debacle on Manafort, the newly hired staffer in charge of fixing this problem. But it reinforces that Trump’s team is playing catch-up. Organizing is not instant; you can’t simply hire a new top guy in New York and immediately expect things in a congressional district in Colorado to change. You need to find people, you need to get up to speed on processes, you need to invest in resources — human and otherwise. None of those things happened in Colorado.

"...The race is now a slog for delegates in the mud outside Stalingrad, and Trump’s only now pulling on his boots."

Ted Cruz is facing another challenge: the task of convincing voters in the state of New York that his "New York values" attack line this year should not be interpreted as any sort of slam on New Yorkers, or on their values. (His explanation: when he said "New York values," he actually meant "liberal Democratic values.")

Since the campaign moved to New York this week, Donald Trump has done his best to remind voters there of Cruz's swipe. Today, John Kasich got in on that action, in a big way.

His new ad echoes Trump. "The straightforward spot plays a ghostly audio of Cruz's remarks from January -- 'I think most people know exactly what New York values are' -- over footage of the city, including the lights that shine from the Freedom Tower to commemorate 9/11. 'Ted Cruz sneered at our New York values,' says a female narrator."

A video from the Kasich campaign skewers rival Ted Cruz for comments he made about "New York values." (John Kasich)

Kasich is actually polling slightly better outside the city, per the most recent Monmouth survey -- in areas like Syracuse, where he stopped today.

...SPEAKING OF SORRY (NOT SORRY): Bill Clinton offered an “almost” apology today for yesterday's tense back-and-forth "with Black Lives Matter protesters who disrupted a campaign event in Philadelphia over his and his wife's support for anti-crime policies in the 1990s that have disproportionately affected African Americans," reported Vanessa Williams.

Former president Bill Clinton stopped short of apologizing on April 8 for an argument with Black Lives Matter protesters at a rally for his wife, Hillary. (Reuters)

"'I did something yesterday in Philadelphia I almost want to apologize for,' Clinton told a crowd of several hundred at Penn State Behrend in Erie, Pa.

"Referring to a young woman who challenged him at the Philadelphia event, Clinton said: 'I realized, finally, I was talking past her the way she was talking past me. We gotta stop that in this country. We gotta listen to each other again.'"

(Clinton's original comments yesterday may have been no mistake, James Hohmann said this morning: "In a year when the drama has mostly been on the Republican side, it made for great political theater. And it gave Bill Clinton another unforgettable 'Sister Souljah Moment.'...")

He also said today he saw a "double standard" at work in the debate over his wife's qualifications to serve as president. He responded to a question about whether "gender was a factor" in the debate by saying she was the most qualified candidate: "I think it's obvious by a country mile and that's all that matters to me."

But, he added, "Yes, I think there are some different standards. Some of them are subconscious." (Late Friday, Sanders campaign manager Jeff Weaver called Clinton's take "ridiculous.")

Hillary Clinton said today she agreed with her husband's latest Black Lives Matter response; "we all need to be listening to each other," she said.

"I think it's important that where we have disagreements and differences ... let's begin to talk and listen to each other," Clinton said.

She seemed less interested in continuing to talk through her disagreement with Bernie Sanders on the question of who is (or isn't) qualified to be president.

"He made those comments [questioning whether she was qualified], and there was no basis for them," Clinton told reporters at Buffalo's Charlie the Butcher restaurant. "It was completely a misrepresentation."

"And he seemed to take them back today. I don't know why he made them in the first place, but I'm going to go on and talk about the issues," she added.

Asked again on Friday in Buffalo if Sanders was qualified, Clinton said simply: "Yes": "As I said, I would take him over Donald Trump or Ted Cruz any day."

Clinton was on a familiar campaign trail upstate, where she's won votes in New York before -- and on Friday, she released an ad that could have run during her re-election campaign, highlighting her accomplishments as senator.

A video released by Hillary Clinton's presidential campaign touts her accomplishments as a senator in New York (Hillary Clinton)

Sanders spent the day burnishing his own New York bona fides with events in Brooklyn: one in front of his childhood home in Modwood, and another in Greenpoint.

Tomorrow, he's making at least four stops in three New York City boroughs, ahead of an unexpected break from the trail just days before the New York primary: a trip to the Vatican next week to speak about social, economic and cultural issues. It isn't just a risky move for Sanders -- the speech already seems to be causing some tension in Vatican headquarters, which has already been burned once this year by the U.S. presidential election.

TRAIL MIX: Dave Weigel explained how a film about Obama’s communist ‘real father’ won at the FEC: “Dreams From My Real Father,” an anti-Obama documentary that showed up in the mailboxes of Ohio voters during the 2012 campaign, is not subject to a donor disclosure requirement, the Federal Election Commission decided in a split decision.

--Obama himself, fundraising on behalf of Democrats in Los Angeles and San Francisco, said he’s "got no patience" for members of his party who are "not that excited about this election."

--Wyoming Democrats caucus tomorrow; you can track full results here

--A follow on last week's Maureen Dowd interview, in case you were wondering (which some people were): Donald Trump now says that none of the women he dated when he was a bachelor had abortions.

--The surrogate star moment of the day again belongs to Ben Carson, who said today that Donald Trump is aware of his Twitter "problem."

--Here's a deep dive into Clinton adviser John Podesta's UFO obsession, pegged to his latest jokes about the potential release of classified alien information during a Clinton presidency.

--Newt Gingrich's presidential campaign is over. Yes, he officially stopped running in 2012, but now it's really over: per an agreement with the FEC, his campaign committee is shutting down despite roughly $4 million in debts remaining to more than 100 vendors, who are now unlikely to ever see that money.

It's an even bigger win for Gingrich than it appears: the move was part of a deal that ended an FEC investigation into allegations that he broke federal law by using his 2012 presidential campaign to promote books that he and his wife wrote. Under the deal, which was reached several weeks ago but revealed in documents released Friday, the former House speaker's campaign was sanctioned for just one violation: failing to properly report a $47,005 debt that the campaign owed him personally for the rental of a mailing list.

--Ted Cruz and John Kasich both made stops in the Bronx this week to reach out to the few GOP voters there. Just how few are there? Here's a stat for perspective: more people have tickets to see the Broadway musical Hamilton tomorrow alone than voted in the 2012 Republican primary in the Bronx. A lot more.

And speaking of Hamilton: Bernie Sanders is seeing the show tonight, because running for president is apparently one of the handful of things someone can do to increase the odds of getting their hands on Hamilton tickets. On a Friday night.

YOUR DAILY TRAIL PIT STOP: John Kasich's feeling just fine these days, thanks for asking.