The most prominent recent successful actions undermining separation of church and state is the faith-based initiative President Bush has put in place and the politicizing of the judicial system. The first is using millions of dollars of taxpayer money to promote Christian values without the checks-and-balances the secular system has in place. The second is an attempt to institute faith-based laws by overloading the judicial system with judges who base their decisions on the Bible instead of the Constitution and rational thought.
If you doubt any of this, try reading any of the following books:
Michelle Goldberg, Kingdom Coming
Damon Linker, Theocons
Richard Dawkins, The God Delusion
Or read through some of the material at any of the following:
The Interfaith Alliance Foundation
Americans United for Separation of Church and State
The First Freedom First Foundation
The American Humanist Association