The rule that allowed Rep. Matt Gaetz (R-Fla.) to single-handedly call for a vote ousting Speaker Kevin McCarthy (R-Calif.) has become a key issue for Republicans as they grapple over who should replace him.

Some are intent on changing the rule, known as a “motion to vacate,” so a handful of House Republicans can never again join with the minority to force a Speaker out and throw the House into chaos. But others who fought for the single-member threshold are defending it.

A group of 45 House Republicans — just over a fifth of the GOP conference — signed on to an open letter last week calling for changes to the “motion to vacate” rule, expressing frustration with the eight GOP lawmakers who joined with Democrats to remove McCarthy.