"They may not be conscripted against their will as the foot soldiers in a federal crusade"

John Paul Stevens' quote is a referral to the power of the federal government and its capability to conscript people into military service. He is suggesting that the federal government ought to not have the ability to require people to serve in the military against their will. He is emphasizing the value of specific flexibility and autonomy, and the right of citizens to make their own decisions about their lives. He is also suggesting that the federal government must not have the ability to use residents as "foot soldiers" in its own causes. This quote is a reminder of the importance of private rights and flexibilities, and the requirement to protect them from the power of the federal government. It is likewise a suggestion of the need for people to be able to make their own choices about their lives, and to not be pushed into service against their will.