在九一一恐怖攻擊後，美國國會立刻通過了美國愛國法。如同美國歷史中所有在緊急時期所通過的任何法律，它成為政府對付異己的重要工具。此外，這個法案也有可能對美國人所最珍惜的公民自由權利作出限制。公民自由權利倡議者對此法案是否有可能和憲法牴觸，提出質疑，並不斷提醒美國公民過去歷史中政府對此自由權利所作的諸多不幸且是不必要的限制。不過，布希政府似乎下定決心要有效地對恐怖主義進行聖戰，因而故意忽略與公民自由權利有關的議題。若是由九一一後美國最高法院所審理的幾個案件來看，已故的美國前首席大法官所宣稱「和公民自由權利相關的法律，在戰時並不會噤聲不言，但它們所發出的聲音倒是會與平常不同。」

The U.S. Congress passed the USA Patriot Act in the aftermath of the September 11th terrorist attacks of 2001. This act, like some of the similar legislations in the history enacted during an emergency period, became an important and effective instrument for government to deal with dissents. It also has the potential to severely curtain civil liberties cherished by the American people. While advocates of civil liberties raise doubt on the constitutionality of the USA Patriot Act and remind American citizens the unfortunate and unnecessary curtailment of these privileges in the past, the Bush administration seems to be determined in its effort to overlook the issues surrounding civil liberties in its campaign against terrorism. Judging from the cases that reach the Supreme Court in the aftermath of September 11, we reluctantly agree with Chief Justice William Rehnquist’s claim that “[t]he laws [on civil liberties] will thus not be silent in time of war, but they will speak with somewhat different voice.”