The Xinhai Revolution of 1911 sought to sweep aside ethnic tensions and unite the Chinese people into a single nation state. In his famous Declaration, the Provisional President Sun Yat-sen stated that the essential foundation of the state is its people. And as Sun and other republicans wanted to establish a single nation state, they knew that the people must be united as far as possible.
There would still be different ethnic groups, to be sure, but in the new Chinese Republic, a common civic citizenship would take priority as part of an attempt to unite the Chinese people into a single political unit.
That was the theory, at any rate. In actual fact, the Xinhai Revolution exploited ethnic tensions by portraying the ruling Qing dynasty as foreigners. The Qing were ethnic Manchus, a minority group within a country dominated by the Han people. In challenging the Qing dynasty, republican revolutionaries played upon the hostility of the majority Han towards the Manchu, who had kept them in a state of subjection for centuries.
Although the language of anti-Manchu hostility was toned down significantly in the aftermath of the Revolution, Manchu culture began a long, sad process of decline, as many Manchu attempted to hide their identities in order to find a place in the new China.