護國戰爭
When Yuan tried to crown himself emperor, Liang convinced Yunnan's military governor, Cai E, to lead the National Protection War against Yuan. Liang reconciled the war with the party's antirevolutionary stance by arguing that the war was not a revolution but an effort to put down Yuan's rebellion against the constitutional republic. Progressive Party branches across the country agitated for the overthrow of Yuan and the party's membership expanded greatly. Yuan's government became paralyzed and he abandoned his scheme. The party's leadership, however, was split into pro- and anti-Yuan factions, thus causing its collapse.