In January, some members of the House Freedom Caucus refused to vote for Kevin McCarthy as House speaker unless he promised concessions. They won. Now, the staunchly conservative group is expanding into an area where they could make a far larger difference: Red states where laws can be passed without support from Democrats. The State Freedom Caucus Network has rapidly taken root in 11 states, promising to make sure that states where Republicans have a mandate legislate like it. While their House counterparts have been criticized as obstructionist — failing to understand the need for compromise in a closely matched...