CLEVELAND — The intraparty insurgency to block Donald Trump from receiving the Republican nomination at next week's convention suffered a crippling blow late Thursday.

The convention rules committee, a panel of 112 GOP convention delegates, defeated a key proposal to amend party rules that could have paved the way for delegates to oppose Trump's nomination on the convention floor.

The measure was carried by Kendal Unruh, a Colorado delegate and rules committee member who has led a group of rogue delegates known as "Free the Delegates."

Unruh's proposal would have changed party rules that bind delegates to the winner of their state's primary, and permitted them to vote their conscience. The amendment needed 28 votes to advance to the convention floor for a full vote of the delegates. It failed overwhelmingly on a voice vote, no tally was taken.

That would appear to close the door on delegates opposed to Trump. However, an outside political group, "Delegates Unbound," still plans to organize a rebellion of some sort on the convention floor. Their effort would appear to be a long shot.

Sen. Mike Lee, a delegate and rules committee member from Utah, supported the conscience clause and spoke after the vote about the danger of delegates relinquishing their power.

"A lot of the focus today has been, understandably, on expanding our party, and making its appeal broader — making those who feel excluded from it feel more included. And, that's important. We send the opposite signal every time we take our rules and we clamp down on our rules further, we make it less possible for delegates to exercise to have a voice in this process," Lee said.

The insurgency always had long odds. But it's been a source of distraction and concern for Republican National Committee leaders. Republican delegates in recent elections have been less enthused by their nominee. But not in recent memory has their been a rebellion that had to be put down.

With the failure of Unruh's conscience clause amendment, Trump would appear to be saved from a potentially embarrassing vote on the floor of his nominating convention.