To form cliques and gather followers, usually implying a negative connotation of colluding or ganging up for a common purpose.
新来的几个同学很快就结党聚群，在班级里形成了自己的小圈子，不太和别人来往。
The new students quickly formed cliques and gathered into a group, establishing their own small circle in the class and not mingling much with others.
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