[多项选择]美国政党唯一的最大弱点是不能在立法机关获得凝聚力。尽管政党内部存在一定的协调性，但是多数党不能执行重要法规的现象并不罕见。在竞选运动期间，存在很强的协调性。初选以后，失利的候选人都承诺要支持党内的候选人。到国会召开会议时，协凋性已经消失。这种现象可以归因于党派政治的分裂本质。国家委员会的成员们只不过是从名义上获得奴仆们效忠的一些封建领主，国会议员把自己的权力建立在狭隘的基础之上。因此，国会议员很可能关心当地的一些特殊利益集团。这种迹象体现在参议院和众议院选举方式的差异之中。在任期更长的参议院，政党的协调性更加显著。

参考答案:The single greatest weakness of American parties is their inability to achieve cohesion in the legislature. Although there is some measure of party unity; it is not uncommon for the majority party to be unable to implement important legislation. The unity is strongest during election campaigns; after the primary elections, the losing candidates all promise their support to the party nominee. By tile time the Congress convenes, the unity has dissipated. This phenomenon is attributable to the fragmented nature of party polities. The national committees are no mote than feudal lords who receive nominal fealty from their vassals. A congressman builds his own power upon a local base. Consequently, a congressman is likely to be responsive to local special interest groups. Evidence of this is seen in the differences in voting patterns between the upper and lower houses. In the Senate, where terms are longer, there is more unity.