The entire text of Pope Benedict's address to the Bishop's published by the VIS is well worth reading and needless to say the issues he deals with are relevant everywhere today not only in the United States can be accessed on the following link.
I would like to highlight some of the points he raised as set out below
[...] "At the heart of every culture, whether perceived or not, is a consensus about the nature of reality and the moral good, and thus about the conditions for human flourishing. In America, that consensus, as enshrined in your nation's founding documents, was grounded in a worldview shaped not only by faith but a commitment to certain ethical principles deriving from nature and nature's God. Today that consensus has eroded significantly in the face of powerful new cultural currents which are not only directly opposed to core moral teachings of the Judeo-Christian tradition, but increasingly hostile to Christianity as such.
[...] The legitimate separation of Church and State cannot be taken to mean that the Church must be silent on certain issues, nor that the State may choose not to engage, or be engaged by, the voices of committed believers in determining the values which will shape the future of the nation
[...] Many of you have pointed out that concerted efforts have been made to deny the right of conscientious objection on the part of Catholic individuals and institutions with regard to cooperation in intrinsically evil practices. Others have spoken to me of a worrying tendency to reduce religious freedom to mere freedom of worship without guarantees of respect for freedom of conscience.
"Here once more we see the need for an engaged, articulate and well-formed Catholic laity endowed with a strong critical sense vis-a-vis the dominant culture and with the courage to counter a reductive secularism which would de-legitimise the Church's participation in public debate about the issues which are determining the future of American society. [...] In this regard, I would mention with appreciation your efforts to maintain contacts with Catholics involved in political life and to help them understand their personal responsibility to offer public witness to their faith, especially with regard to the great moral issues of our time: respect for God's gift of life, the protection of human dignity and the promotion of authentic human rights".