Even though voters didn't head to the polls Saturday, Cruz's strength here could help deny Donald Trump the 1,237 delegates that he needs to clinch the nomination.
Cruz's victory Saturday, combined with delegates he had already earned, hands him 30 of the 37 delegates across the state who are legally bound to support him on the first ballot at the convention, along with four other delegates who gave him verbal commitments of support.
"Today was another resounding victory for conservatives, Republicans, and Americans who care about the future of our country," the Cruz campaign said a statement. "Utah, North Dakota, Wisconsin, and tonight's incredible results in Colorado have proven this: Republicans are uniting behind our campaign because they want a leader with real solutions who will bring back jobs, freedom, and security."
Earlier in the afternoon, Cruz had urged state Republicans here at the Broadmoor Arena to help him defeat Trump.
"If we continue to stand united, we are going to win this Republican nomination. We are going to win the general election. We are going to win the state of Colorado and we are going to turn this country around," Cruz said to huge cheers from the arena floor.
In yet another sign of his airtight ground game, Cruz spoke before a huge screen displaying his slate of delegates for the final 13 spots, and he noted that his slate was also printed on the bright orange T-shirts that his many volunteers were wearing on the state convention floor.
Trump's campaign, by contrast, initially distributed fliers listing the campaign's national delegate candidates that were riddled with errors. The flier displaying the Trump slate is supposed to be the tip sheet that party members use to fill out their ballot. But on the first slate that the Trump campaign was giving out, more than a half dozen of their delegate candidates were listed with the wrong delegate number. At least one of the delegate numbers corresponded to a delegate supporting Cruz.
The Trump campaign reprinted the flier, but the second flier also included several errors.
Before the voting began, Trump campaign adviser Patrick Davis said in an interview that the team had been given "incomplete" information by the Colorado Republican Party about delegate numbers.
Later in the evening, as the votes were being counted, senior Trump adviser Alan Cobb said several supporters had told the campaign that their ballot number had changed numerous times or that their name did not appear on the party's official list of national delegate candidates even though they had filled out the proper paperwork.
Alan Cobb, the senior adviser to Trump, said the campaign was looking into the reports of balloting problems and was not ruling out a challenge to seating the Colorado delegation at the national convention in July.
A spokesman for the state party said it was looking into the reports but had no immediate comment.
It was unclear how much confusion that caused, but the Trump campaign has acknowledged that it did not expect to win any delegates in Colorado.
While there was fervent enthusiasm for Cruz, former New Hampshire Sen. John E. Sununu, who was Ohio Gov. John Kasich's surrogate at the gathering, was greeted with polite applause.
"We've got to unify behind that candidate who will win," Sununu told the crowd, pointing to Kasich's strength in general election polling matchups with Hillary Clinton. Kasich, however, had not won any delegates as of Saturday afternoon.
Trump campaign surrogate Stephen Miller, a policy adviser to the real estate magnate, drew a warmer response by opening his speech with a focus on the issue that helped carry Trump to the top of the Republican field: Immigration.
"Do you think the United States of America needs to secure its border?" Miller asked the crowd, which shouted "Yes" in response. Before even mentioning Trump's candidacy, Miller went on to read letters from parents who he said had lost their children to "illegal immigrant violence."
"These Americans deserve a voice and I am going to give it to them today," Miller said. "It's the powerless who are standing up behind Mr. Trump."
Cruz in control
Cruz dominated the intricate delegate selection process of the Colorado Republican Party, and in this pivotal swing state, a strong campaign organization has often made the difference between defeat and victory in the race to the White House.
In this first round for the GOP, Team Cruz once again proved its mettle -- far outpacing the efforts of Trump and Kasich in the scramble for delegates at each of the congressional district gatherings this week.
By late Friday, Cruz had swept all the available delegates in the state's seven congressional districts.
In the final rounds of a messy and chaotic process Friday, candidates vying to be one of Colorado's delegates lined up along the walls of the ballroom at a Doubletree hotel here waiting their turn to deliver campaign speeches. "You have 10 seconds. Go!" a party official barked as the first candidate stepped to the microphone Friday morning.
Cruz volunteers seemed to be everywhere, working the hallways where party members were crammed shoulder to shoulder among vendors peddling Cruz infinity scarves and Trump-style "Make America Great Again" hats. In one corner, a hot pink handwritten sign lured the undecided over to talk to "Cruz Persuasion Teams."
The ballroom floor was littered Cruz campaign slates (the tip sheets indicating which delegates are endorsed by the campaign). Scattered across the room were glossy copies of the "Donald Trump Voter Guide," which is actually an anti-Trump pamphlet distributed by one of the super PACs that is trying to defeat him.
Amid all the jostling, shouting and chaos throughout the day Friday, delegates aligned with Cruz won again and again.
Trump still maintains a wide lead over Cruz in the delegate count as the two candidates attempt to win the 1,237 delegates needed to clinch the Republican nomination.
Antipathy toward Trump
But at a time when a contested convention looks increasingly likely, there was palpable disdain for Trump's candidacy among the GOP faithful here. His string of unforced errors, nasty tweets and controversial policy statements in recent weeks have clearly taken a toll.
"The momentum against Trump at the activist level is just frothing," said Josh Penry, a former state senator who was Marco Rubio's state chairman in Colorado. "There was a time when Trump could have competed in Colorado. That time has long since passed. ... Among the activists, the tide has turned against him dramatically."
Trump canceled a planned rally in Colorado this week as he focused his efforts on New York, which holds its critical primary on April 19.
While Trump had some fervent supporters here at the state convention, it was clear from the speeches delivered by delegate candidates that his appeal has worn thin for many Republicans -- a testament to how much work the real estate magnate would have to do to unite the party if he becomes the nominee.
At Thursday night's gathering for Colorado's 7th Congressional District, 19-year-old student Angel Merlos urged the crowd to elect him as a Cruz delegate to the convention, because he said the nation's values and morals were at stake if Trump were to become the Republican nominee.
"Morality is about how you act, how you speak, and how you carry yourself," Merlos said in interview after his brief speech in Arvada. "I believe Trump has no morals because he lies about many things. ... He contradicts himself on everything."
"He thinks he knows what will help the immigration problem, but he doesn't," Merlos continued. "He talks about a wall -- that may do something. I don't know exactly what it will do. But he uses immigrants to help him build his buildings, and yet he's so cruel and harsh" when he talks about them, Merlos said.
Delegate candidate David Head ran as an "unpledged" delegate in the hope of serving as a voice against Trump on the floor of Republican convention in July.
"I think he would be a disaster for both the Republican Party and the country," said Head, who owns an insurance business in Westminster, Colorado, with his son.
"He confuses intimidation and bluster with straight talk and honesty. I think he is anti-woman. I think he is saying whatever he thinks will sell to get him a vote, and I think he's playing on the fears and prejudices of a lot of people to intimidate people into voting for him."
Libby Szabo, a Jefferson County Commissioner who won a slot as a Cruz delegate to the national convention, said as a conservative, she was troubled by Trump's recent comments about punishing women who have illegal abortions. (Trump backed off that position after an uproar from opposite sides of the political spectrum.)
"I like that he has started a dialogue in our party that we need to have. I just don't see him as being consistent," Szabo said. "One week he says one thing, the next week he says another thing."
Trump campaign looks to step up operation
Beyond the simmering anti-Trump sentiment here, Cruz's strength in the delegate chase in Colorado (as well as states like North Dakota, Louisiana and Tennessee) has once again exposed the deficiencies of Trump's organizing operation, which is scrambling to catch up.
Trump's allies insist there is still time to streamline their delegate wrangling operation and time to persuade even those who are resistant to his brand of politics at this moment.
One Trump adviser said they entered the Colorado GOP contests with the expectation of winning "zero delegates" -- and were pleased at the end of the day Friday that they had won two alternate delegates pledged to Trump in Congressional District 4.
"This is just the beginning of a four-month process to convince the unpledged delegates and alternates in Colorado that Donald Trump means what he says, he's going to make America great again," said Davis, a Colorado-based political consultant who joined the Trump team this week after Trump's campaign manager fired their Colorado state director.
In conversations with Cruz supporters, Davis brushed off questions about Trump's poor standing in general election match-ups with Hillary Clinton, arguing that "polls taken today, six months away from November, are garbage, and will not be predictive on election day."
As for Cruz's clear organizational advantage, Davis said Trump's team remains undaunted.
"This is an insider's game," Davis said, as he waited for the final votes of the day to be tabulated. "Nowhere in America, including Colorado, are insiders the heart and soul of the Trump campaign."
But the question is whether Trump can get geared up in time to win that insider's game.
His campaign announced an expanded role this week for veteran GOP operative Paul Manafort, who is managing convention activities for Trump -- just as he did for the presidential campaigns of Gerald Ford, Ronald Reagan, George H.W. Bush and Bob Dole.
Becky Mizel, a Trump volunteer who was the former chair of the Pueblo County Republican Party in Colorado, said she wasn't discouraged by Trump's poor showing in the state.
"Cruz has a very strong organization here," she said when asked about the obstacles her candidate had faced. One of Cruz's most powerful allies, she noted, was the Rocky Mountain Gun Owners, which circulated ubiquitous blue fliers touting Cruz delegates at every voting location this week.
Mizel credited the head of the group, Dudley Brown (who she counts as a friend), with "organizing the Cruz machine with the legislators who have decided to go and block Mr. Trump."
"The average person on the street is working or raising their kids -- they aren't political junkies like the caucus attendees are -- and those are the people that are attracted to Mr. Trump," she said.
At the same time, Mizel said she was relieved that the Trump campaign now seems to grasp the gravity of the task before them as they prepare for the possibility of a contested convention.