Paul Manafort, the newly installed convention manager for Donald Trump’s presidential bid, made an important — and under-appreciated — point during an interview on Sunday with “Meet the Press” host Chuck Todd. Here’s Manafort talking about the campaign and his role in it:

“Trump was doing very well on a model that made sense, but now, as the campaign has gotten to the end stages, a more traditional campaign has to take place. And Trump recognized that and is now reaching out not just with me, but with others as well that you’ll start to see come in.”

What Manafort is acknowledging is that Trump ran a very effective insurgent campaign for months and months. But what happened sometime over the past six weeks or so is that Trump became the dog that caught the car. The insurgency worked. Trump got to the front of the pack. But while insurgencies are good at being, well, insurgent, they are less good at building a governing coalition.

Trump’s brash personality and his ability to generate massive amounts of media attention were perfectly suited to the insurgency portion of his campaign. He controlled the narrative of the race from virtually the second he entered it in June. Unfortunately for Trump, his seeming unconcern with specifics and disdain for rules fits far less well in this trench warfare stage of the race.

Consider what happened over the weekend in Colorado, where rival Ted Cruz walked away with all of the state’s 34 delegates. The WaPo’s Ed O’Keefe wrote of Colorado: “At the state GOP convention, Trump supporters distributed glossy fliers urging people to vote for a slate of their preferred candidates. But several names were misspelled or assigned the wrong ballot number.” Trump forces insisted that they weren’t competing aggressively in Colorado and noted that they had just installed a new state director. Trump himself fell back on his preferred stance when things don’t go his way: complaining on Twitter:

“How is it possible that the people of the great State of Colorado never got to vote in the Republican Primary? Great anger – totally unfair!”

But what happened in Colorado exposes just how unprepared Trump is for the long slog of delegate selection that will fill the next few months. He has run a campaign aimed at cruising to and over the 1,237-delegate threshold he needs to formally be the Republican nominee. Except now he’s in a race in which 1,237 can be achieved only through the grinding, un-glorious daily, weekly and monthly accruing of delegates inclined toward Trump on not just the first ballot but on the second, the third and beyond.

Enter Manafort and the promised “more traditional” campaign.

The question now is whether Trump realized too late that he was running in a race for which he was poorly equipped to succeed. As Frontloading HQ’s Josh Putnam notes, about 68 percent of all Republican delegates have been allocated but just 28 percent actually have been selected. A bit of math tells you that 72 percent of the delegates to the Republican National Convention have not yet been selected, meaning — at least in theory — that Manafort/Trump still have plenty of time to fix their delegate problem.

But that assumes that Manafort can snap his fingers and build even the skeleton of organizations in the states yet to select their delegates. Which, of course, he can’t. And the truth is that there is very little Trump organization even in many of the states he won. Trump prevailed because he was the momentum and energy candidate. Organization, as lots and lots of losing candidates can tell you, can’t overcome organic energy and passion. That was the key to Trump’s success.

It also might be the central element of his undoing. He didn’t need real organizations to win. So he didn’t build them. And now that he needs them, he doesn’t have them. Manafort’s task is to not only build these organizations but to do it quickly enough that what happened in Colorado over the weekend doesn’t keep happening across the country. It’s a very tall task.

(c) 2016, The Washington Post · Chris Cillizza