WASHINGTON — The Republican National Committee moved Friday to consolidate its presidential nominating process in 2016, a pre-emptive effort to avoid a drawn-out campaign that many in the party say could imperil their effort to reclaim the White House.

“We have been saying for months that we were no longer going to sit around and allow ourselves to slice and dice for six months,” Reince Priebus, the party chairman, said in remarks hailing the vote on the rule changes.

The package, which cleared the 168-member committee with just nine dissenting votes, left Iowa and New Hampshire in the traditional roles of first caucus and first primary, followed by South Carolina and Nevada nominating contests, all in February. Other states are allowed to hold their primaries and caucuses starting on March 1.

After the first two weeks in March, states can hold winner-take-all elections, which will deliver large troves of delegates and are intended to yield a prospective nominee early in the process. States that violate the new rules would forfeit most of their delegates and alternates to the national convention.