Donald Trump is devastated after Senator Ted Cruz defeated him in Colorado. Trump took to Twitter to criticize the state’s process for selecting national delegates, suggesting the system was unfair.

“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!” the Republican presidential candidate tweeted questioning the selection process.

“The people of Colorado had their vote taken away from them by the phony politicians. Biggest story in politics. This will not be allowed!”

Trump rips ‘rigged’ US election system after Colorado loss https://t.co/HG2S5e9ap7 pic.twitter.com/AIUl59L5d6 — ABS-CBN News Channel (@ANCALERTS) April 12, 2016

Paul Manafort, Trump’s convention manager, accused Cruz’s camp of using “Gestapo tactics” to win over delegates. “You go to these county conventions, and you see the Gestapo tactics—the scorched-earth tactics,” Manafort told NBC’s Meet the Press, adding that Cruz may have used dirty tactics to win over delegates. “It’s not my style, and it’s not Donald Trump’s style… But it is Ted Cruz’s style.”

Manafort confirmed they will be filing complaints because the Cruz campaign is “not playing by the rules.” Cruz has already won 34 delegates.

On Sunday, Donald Trump tweeted that the Texas senator used underhanded techniques to win over delegates. “I win a state in votes and then get non-representative delegates because they are offered all sorts of goodies by Cruz campaign. Bad system!” he wrote.

I win a state in votes and then get non-representative delegates because they are offered all sorts of goodies by Cruz campaign. Bad system! — Donald J. Trump (@realDonaldTrump) April 10, 2016

Responding to Trump’s accusation against the senator, Cruz campaign spokeswoman Catherine Frazier said Trump is only distracting voters from their failure.

“It’s no surprise that Trump’s team will lash out with falsehoods when facing a loss to distract from their failure, as they have the entire time,” Frazier said of Trump’s allegations. “We have earned our success by working hard to build a superior organization and are working within the process and rules that have been established—which has led now to four consecutive wins, 12 wins total.”

Cruz camp response from @catblackfrazier on Trump’s tweet that Cruz is offering “goodies” to get delegates: pic.twitter.com/cYePjyM62D — Ashley Killough (@KilloughCNN) April 10, 2016

The Cruz campaign started wooing Colorado delegates months before the convention and intensified their campaign efforts when they enlisted U.S. Rep. Ken Buck, R-Windsor, as state chairman. The campaign also got the support of the Rocky Mountain Gun Owners, Gun Owners of America, and several religious groups.

Cruz has a strong following in Colorado, and the Trump campaign was aware they had a slim chance of winning in the state. The senator won all 21 delegates in the seven congressional district conventions in the state over the past week.

Trump’s already slim chance of winning over delegates in Colorado was worsened by errors on his ballots.

During the Colorado state convention on Saturday, the Trump campaign may have unintentionally caused its supporters to vote for a delegate who supports his rival when they distributed sample ballots bearing wrong numbers for seven delegates. The error was corrected except for four numbers.

Cruz sweeps Colorado as Trump campaign issues error-filled ballots: https://t.co/uyzx81bSs8 (Pic: The Gazette/AP) pic.twitter.com/5JtoSYbnPE — MSNBC (@MSNBC) April 10, 2016

Some speculate that the error on the ballot could have led Donald Trump voters to choose delegates who support Cruz.

A Trump campaign staffer told The Guardian that their numbers were right at the time of printing but thought the problem was caused by the state party’s constant revisions to the delegate order. However, he noted that “it’s unlikely to make any difference in the final result.” Both Ted Cruz and John Kasich reportedly had every number on their respective slates right.

Many Donald Trump supporters in Colorado have expressed their frustration over the results of Saturday’s convention. The Trump staffer said that their candidate’s weak presence in the state contributed to their devastating loss. On Tuesday, Trump’s camp fired the staff member assigned to supervise Trump’s Colorado operation.

[Photo by Charles Rex Arbogast/AP Images]