UPDATE: Chaos in Cleveland, Anti-Trump Forces Walk Out After Controversial Ruling

UPDATE III -- Despite anti-Trump forces submitting signatures from the majority of 9 to 11 state delegations, the convention chair just asserted that enough of those delegates had withdrawn their names from that effort to negate a roll call vote under the rules. All hell broke loose on the floor, as the podium was abandoned for a long stretch, amid loud protests. Multiple delegations have walked off the floor in protest:

Loud booing of chair for not allowing roll call vote on rules #RNCinCLE
— Rick Klein (@rickklein) July 18, 2016

ICYMI - WATCH: Here's what happened during first vote on #GOPConvention Rules #RNCinCLE https://t.co/QFtnVYwh90
— CSPAN (@cspan) July 18, 2016

Anti-Trump delegations don't # believe requisite roll call-triggering signatures were withdrawn. (What's the proof?)

They're walking out.
— Guy Benson (@guypbenson) July 18, 2016

Q: If "destroyed" Never Trump "fringe" would've failed on roll call vote, why not have an expedited one, let process play out, move on?
— Guy Benson (@guypbenson) July 18, 2016

More potential chaos tomorrow?

.@BretBaier saying #NeverTrump may get another bite at apple tomorrow, during nomination process. Time to challenge signatures claim?
— Guy Benson (@guypbenson) July 18, 2016

UPDATE II - Sounds like the party may be resigning itself to this vote moving forward...and that the Trump campaign was caught off guard (!) by this push. Was Paul Manafort too busy making pro-Putin changes to the platform to foresee this?

Trump source: camp officials on floor cajoling delegates to reject effort to upend convention rules. Adds camp didn't see this coming
— Jim Acosta (@Acosta) July 18, 2016

UPDATE -- Power struggle underway to prevent this vote, with some serious strong-arming being reported. The optics look like the GOP establishment is trying to rig the system to shut down a legitimate vote put into motion by conservative insurgents under the rules:

Last week, the 'Never Trump' contingent on the convention rules committee fell well short in their effort to compel a full floor vote -- in which all 2,400-plus delegates would cast ballots, up or down -- on the pro-Trump package of rules that would govern the Cleveland gathering. The ultimate goal was to "unbind" all delegates, allowing them to vote their consciences on the convention's first presidential ballot, rather than being required to support a candidate based on their state's primary or caucus results. They failed. But it now appears that Trump opponents have managed to gather the requisite signatures to trigger a convention-wide vote on the rules package through an alternative means. Politico reports:

Republicans looking to unseat Donald Trump as their party’s presidential nominee appear to have the signatures they need to force a full vote on the national convention rules, a move intended to provide a platform for anti-Trump voices and to embarrass the billionaire. To force that vote, the faction would need signatures from the majority of delegates from 7 states or territories. According to documents provided to POLITICO, they have a majority of signatures from 9: Colorado, Washington state, Utah, Minnesota, Wyoming, Maine, Iowa, Virginia and Washington, D.C. The group says former New Hampshire Sen. Gordon Humphrey has submitted the signatures to the convention secretary. Submitting those signatures would force a roll call floor vote from all 2,472 delegates to the convention on the Republican National Committee rules that an 112-member panel voted through last week.

Of the nine states and territories listed, only two (Washington and Virginia, narrowly) were carried by Trump during the Republican primary cycle. The rest have delegations heavily disposed towards Ted Cruz (who won five of those contests) and Marco Rubio (who won two). There were rumors that the convention secretary might effectively "disappear" in order to thwart this process, which requires the gathered signatures to be formally submitted to her. That apparently did not happen:

Probably why she finally accepted, per dissident delegates. https://t.co/X2ezXWYeaG
— David M. Drucker (@DavidMDrucker) July 18, 2016

Petitions filed & accepted. #RNCinCLE https://t.co/dqkvRIsULa
— David M. Drucker (@DavidMDrucker) July 18, 2016

If this convention floor roll call vote were to occur, it's extremely unlikely that the "free the delegates" group's desired outcome would prevail. In other words, the rules will almost certainly be adopted as-is, but Trump critics within the party would be given an opportunity to very publicly signal their displeasure through what effectively amounts to a "no confidence" vote. That would be an embarrassment for the GOP, and it would be televised to the world in the middle of a quadrennial event that has become a highly-choreographed pageant of unity in modern times. For that reason, RNC establishment officials are reportedly desperately working behind the scenes to try to shut it down. Stay tuned...

RNC officials are scrambling to pull aside delegates from roll call signatories in effort to head off a vote
— Zeke Miller (@ZekeJMiller) July 18, 2016

Here are two prominent 'Never Trumpers' urging delegates to vote down the committee-produced rules package. They probably know that this push is doomed, but they're aiming to garner as many protest votes as possible to highlight that Trump does not represent a substantial portion of the party, even at his nominating convention:

Every conservative right now should be calling every delegate they know at the RNC to tell them to reject the rules package.
— Erick Erickson (@EWErickson) July 18, 2016

One can be pro-Trump and support a roll call vote on the Rules. It should happen. What's wrong with a vote??
— Amanda Carpenter (@amandacarpenter) July 18, 2016