LAST 4-1-21政治题一道看不懂

21. Whenever a major political scandal erupts before an election and voters blame the scandal on all parties about equally, virtually all incumbents, from whatever party, seeking reelection are returned to office. 当选举前的一个丑闻被选民归咎于所有政党时，各党派的在职者都会连任However, when voters blame such a scandal on only one party, incumbents from that party are likely to be defeated by challengers from other parties. 但是，当选民指责某一个政党时，这个政党的在职者就会被击败The proportion of incumbents who seek reelection is high and remarkably constant from election to election.在各个选举中，要求改选的现任者的比例总是很高很稳定
If the voters’ reactions are guided by a principle, which one of the following principles would best account for the contrast in reactions described above?contrast是——同样是有丑闻，但是，大家都有的时候就能连任，只有一个人有的时候那个人就下台——同样的原因导致不同的结果
(A) Whenever one incumbent is responsible for one major political scandal and another incumbent is responsible for another, the consequences for the two incumbents should be the same.题干只讲了对于同一个丑闻的情况
(B) When a major political scandal is blamed on incumbents from all parties, that judgment is more accurate than any judgment that incumbents from only on party are to blame.无关
(C) Incumbents who are rightly blamed for a major political scandal should not seek reelection, but if they do, they should not be returned to office.似乎不在表述voters的原则
(D) Major political scandals can practically always be blamed on incumbents, but whether those incumbents should be voted out of office depends on who their challengers are.这个很容易排除是吧
(E) When major political scandals are less the responsibility of individual incumbents than of the parties to which they belong, whatever party was responsible must be penalized when possible.和丑闻有关，只要可能就要受到惩罚（我的理解是：voters的言下之意是，如果都有丑闻，没有办法惩罚；如果有个别有，就用下台来惩罚）

答案是E,我完全不明白，请大虾执教

But if the party which is involved into scandles will be penalized, then, why "The proportion of incumbents who seek reelection is high and remarkably constant from election to election" ？

Looking forward reply. Thank you