As a result of an agreement signed by Great Britain and Ireland in 1998, Northern Ireland

The correct answer is McCarthyism.

Margaret Chase Smith was one of the few members of Congress willing to stand up to Joe McCarthy and his constant abuse of power. Joe McCarthy was trying to get rid of communism in the US. However, the means he used to do this were through intimidation and faulty logic. Margaret Chase Smith stood up to him and references his actions in the excerpt above.

When she discusses those who shout the "loudest" often ignore the rights of citizens she is talking directly about Joseph McCarthy.