Unless a new contender emerges before the leadership vote next Thursday, the new majority leader will have a less conservative voting record than the man he is replacing.

The fight for Mr. McCarthy’s old job would then pit Representative Peter Roskam of Illinois, whose voting record is similar to Mr. McCarthy’s, against Representatives Steve Scalise of Louisiana and Marlin Stutzman of Indiana, who have more conservative records.

A Roskam victory would mean that after a week and a half of turmoil, Republicans would have traded a leader from suburban Richmond for one from suburban Chicago. The aggregate rating of the House majority leader and majority whip by the American Conservative Union would have slipped from 84.25 over the past two years to 78.5. A perfect conservative score would be 100.