There's a recurring question among the Republicans gathering in Colorado at state and local conventions to choose delegates this week: "Where's Donald Trump?"
Colorado is a rare state where party officials choose delegates without any input from a primary or caucus vote. The bulk of the state's 37 delegates will be picked at a series of Congressional district conventions on Friday and a state convention on Saturday in Colorado Springs. Prospective delegates can run as unaffiliated free agents or pledge to back a candidate.
With the odds rising that no candidate will secure the 1,237 delegates necessary to clinch the nomination, the race increasingly hinges on this kind of Byzantine state-by-state delegate selection process. Trump has won by far the most pledged delegates, who are required to support him on the first ballot. Most will be free to vote for whomever they chose after that and the candidates generally have little input into picking.
There is little evidence Trump's campaign is up to the task so far, however, giving Senator Ted Cruz a major opening to overtake the front-runner on the Cleveland convention floor.
Colorado will provide a major test of the dueling campaigns when it comes to gaming the delegate process.
Cruz's operation is headed up by Congressman Ken Buck, his state chairman and a mainstay in Colorado's GOP. Trump's campaign has no official state chair and it's not clear who's running things. James Baker, the campaign's initial point person for the state, was fired this week amid infightingbetween senior staff, according to a Politico report. Baker did not respond to an email from MSNBC on Wednesday.
In an ominous sign for Trump, two Colorado Congressional districts already held their conventions this week and Cruz swept both events, installing six delegates pledged to support him come convention time.
State representative Justin Everett, who was picked as a Cruz delegate, said the campaign kept in constant contact with him and other candidates for delegate by phone and email. They helped draw up talking points for speeches, distributed pro-Cruz delegate slates, and briefed participating local officials to make sure they didn't fracture support.
When the convention came, Everett said they faced some resistance from supporters of Ohio Governor John Kasich. But what surprised him was the lack of any pushback from Trump.
"It seems like an epic fail on the Trump campaign's part," he said. "I don't see anyone organizing."
Republicans unaffiliated with any campaign echoed his assessment, describing an active Cruz effort and a practically invisible Trump campaign.
Joy Hoffman, chairwoman of the Arapahoe County GOP and an unaffiliated alternate delegate, said Cruz "networked like there's no tomorrow" ahead of the congressional convention and built an "extraordinary" ground game early on.
As for Trump, there was little operation of which to speak. "It's rather surprising," she said.
Peg Cage, chairwoman of the Boulder County GOP, said she had seen plenty of Cruz activity ahead of Friday's selection process and little from Trump.
"I know there are some really staunch Trump supporters, but I haven't seen any Trump slates come cross my desk yet," she said. "I know there are a lot of Cruz slates and a lot of the candidates for national delegate have expressed their preference for Cruz."
"18 to 1: I'll take that ratio any day of the week," Cruz boasted in his victory speech in Wisconsin on Tuesday night.
While it's not clear how committed those delegates are to Cruz, his supporters successfully blocked several delegates from the state GOP slate who Trump's campaign had identified as possible supporters.
North Dakota and Colorado may be naturally unfriendly states to Trump based on the primary map thus far. But strategists also see trouble for Trump in Arizona, a state where he dominated and - unlike in Colorado - enjoys support from some prominent Republicans.
Arizona's GOP chooses its delegates through a complicated multi-step process that requires picking supportive state delegates at local assemblies who go on to choose the national RNC delegates at the state convention. All of the state's delegates will be bound to Trump initially, but they can support any candidate the want if Trump fails to win on the first ballot. That makes locking down reliable supporters absolutely critical.
"The only campaign I see aggressively organizing is Cruz," Nathan Sproul, an Arizona-based Republican strategist, told MSNBC in an e-mail. "I did this for Romney in 2012 and know how important getting the right state delegates is. As best I can tell, Cruz is sweeping most state delegate slates."
It's not just Cruz and Kasich that Trump has to worry about either. The anti-Trump group Our Principles PAC, which has spent millions on ads opposing his candidacy, is increasingly devoting its focus to the delegate selection fight.
"It's an Achilles Heel for him," Our Principles co-founder Katie Packer told NBC News. "They just don't have the organization you have to have to be the nominee.
Trump is looking forward to a friendly primary in his home state of New York on April 19 after losing Wisconsin, and if he makes it to 1,237 delegates before convention, all these esoteric delegate fights will be a footnote. His so-far disinterested delegate effort, though, means he'll have zero margin of error. If Trump doesn't win on the first ballot - even by one delegate - the party looks poised to have ample resources to shuffle him off the stage.
This article originally appeared on MSNBC.com.