Such rhetoric makes taking over the debates easier to sell to the committee’s more conservative members. But what party leaders are principally concerned about is reducing the number of debates to avoid a repeat of the 2012 campaign when a series of insurgent candidates used the forums — 20 in all — to draw attention to their candidacies. Some party leaders say they believe that the number of debates pushed Mitt Romney to the right in a way that contributed to his loss to President Obama.

Party leaders want to tighten their grip on a presidential primary season they believe has grown unruly and too long. This year, the party moved to set the nominating calendar by scheduling the first four contests — Iowa, New Hampshire, South Carolina and Nevada — for February, allowing other states to begin voting in March and holding winner-take-all primaries starting March 15.

Party officials are also moving to find a city that can accommodate a convention in late June, earlier than usual to give the party’s nominee a head start on raising money for the general election.

Taken together, these procedural steps could thwart an underfunded insurgent who needs the free exposure of televised debates and would be hurt by a series of rapid-fire contests in March that could be tilted toward an establishment-backed contender.

A few conservative stalwarts on the committee are nervous about the establishment’s consolidation of power over the primaries. “Do we want a committee of the national committee, which will surely be controlled by the national chairman, picking which candidates participate in all Republican presidential debates?” asked Morton Blackwell, a committeeman from Virginia.