Republican Convention Floor Erupts in Chaos as Never-Trump Forces Thwarted The never-Trump forces are trying to change the rules.

 -- The floor of the Republican National Convention erupted into chaos Monday amid an attempt by never-Trump forces to change the event's rules. The bid was defeated, thwarting the effort to block the real estate mogul's path to the nomination.

Delegates engaged in dueling chants of "Roll call vote" and "USA" on the floor after Rep. Steve Womack of Arkansas, the presiding chairman, forced a voice vote and judged that those who favored the existing rules prevailed. Colorado's delegation walked off of the floor in protest amid the chaos.

The push to force a roll call vote was defeated, closing the last available avenue for the never-Trump movement to unbind delegates. Donald Trump amassed more than 1,237 delegates through the primary season — enough to secure the nomination. But there was an effort to release some of those delegates so they could vote for other candidates.

Womack returned after a brief absence to call for a second voice vote. Once again he ruled in favor of the "aye" votes. He then recognized the Utah delegate standing next to Sen. Mike Lee to offer a motion requesting a roll call vote.

According to Rule 39, a roll call vote may be called if the majority of delegates from at least seven states or jurisdictions demand a vote on the floor.

Delegates Unbound, which was hoping to let GOP delegates vote for whomever they choose, said earlier today it had the support necessary to force a roll call vote on the rules package. "Despite every obstacle thrown in our way, the movement of all the stakeholders involved in this effort have gained a majority of the delegates in 10 states," Delegates Unbound co-founder M. Dane Waters said in a statement today. "Now we take this fight to the floor."

This afternoon, however, Womack said that only six jurisdictions supported a roll call vote, but he did not reveal which ones. The Utah delegate asked which ones had backed out, but his microphone was turned off. Instead, Womack declared that the rules package passed.

The roll call vote would have been an incremental step toward unbinding pledged delegates who are committed to voting for Trump but would like to vote for another candidate. If this had succeeded, delegates on the floor would have needed to reject the entire rules package passed by a rules committee earlier today, sending it back to the committee for reconsideration.

ABC News' Rick Klein and Shushannah Walshe contributed to this report.