Sentence:  Lacking the respected and effective <WSD>institutions</WSD> that consensus helps provide , minority parties , such as the P.D.I. in 1957 and the progressive Istiqlal faction in 1958 , clamor for elections when out of power , but are not at all certain they wish to be controlled by popular choice when in power . 
Meaning of the word marked with <WSD> tags:  an organization founded and united for a specific purpose