In its 1903 decision in the case of Lone Wolf v. Hitchcock, the United States Supreme Court rejected the efforts of three Native American tribes to prevent the opening of tribal lands to non-Indian settlement without tribal consent. In his study of the Lone Wolf case, Blue Clark properly emphasizes the Court's assertion of a virtually unlimited unilateral power of Congress (the House of Representatives and the Senate) over Native American affairs. But he fails to note the decision's more far-reaching impact: shortly after Lone Wolf, the federal government totally abandoned negotiation and execution of formal written agreements with Indian tribes as a prerequisite for the implementation of federal Indian policy. Many commentators believe that this change had already occurred in 1871 when - following a dispute between the House and the Senate over which chamber should enjoy primacy in Indian affairs - Congress abolished the making of treaties with Native American tribes. But in reality the federal government continued to negotiate formal tribal agreements past the turn of the century, treating these documents not as treaties with sovereign nations requiring ratification by the Senate but simply as legislation to be passed by both houses of Congress. The Lone Wolf decision ended this era of formal negotiation and finally did away with what had increasingly become the empty formality of obtaining tribal consent.
As an element in the argument presented by the author of the passage, the reference to Blue Clark's study of the Lone Wolf case serves primarily to

解析:举例作用题
例子服务对象:Blue Clark properly emphasizes the Court’s assertion of a virtually unlimited unilateral power of Congress (the House of Representatives and the Senate) over Native American affairs. But he fails to note the decision’s more far-reaching impact:
A. 指出这件事情在印第安历史上还没有受到学者足够的关注
B. 支持LW比1871国会的行为影响更大的观点
C. 挑战最高法院关于国会对印第安事务无限制的单方面权利的判定
D. 反对将1871国会行为看作是联邦政府和印第安部落正式协商终结的观点
E. 介绍一个关于LW的观点,作者后面详细论述

