A strong majority of anti-establishment conservatives in the House Freedom Caucus voted on Wednesday night to support Representative Paul D. Ryan of Wisconsin for House speaker, assuring that he will have the votes to secure the post next week and averting a leadership crisis for Republicans. Mr. Ryan indicated that he was prepared to seize the gavel and try to bring unity to his party, which has been riven over how House leaders exert authority over members. That fight had become so bitter that it forced the resignation of Speaker John A. Boehner and derailed the candidacy of the majority...