That's a great question. Muslim Americans are now playing a leading role in intra-Muslim dialogues on the importance of freedom of religion and values of religious pluralism. They do so at a formal level, through participating in governmental and non-governmental dialogues abroad, and at the informal level, through their social and religious networks. At the grassroots, you can observe this taking place by visiting your local interfaith dialogue groups. One concrete example: during President Bush's administration, the State Department regularly funded the trips of interfaith groups from the United States to Muslim-majority areas of the world. I was part of one such delegation sent to Mindinao in the Philippines. Muslim participants included Rafia Zakaria, a women's rights advocate who serves on an Amnesty International board; Zahid Bukhari, a Muslim American scholar; and former Islamic Society of North America Sec'y General Muneer Fareed.
For evidence of this at the intellectual level, you can read the work of Muslim Americans such as Khaled Abou El Fadl, Amina Wadud, Ingrid Mattson, Omid Safi, Seyyed Hossein Nasr, the late W. D. Mohammed, and Eboo Patel. These scholars and leaders all see religious tolerance and freedom of religion at the heart of Islam, and often quoting the Qur'an that there can be "no compulsion in religion," they call on fellow Muslims to protect these precious Islamic values.