West, the assistant attorney general for the department's Civil Division, once represented "American Taliban" John Walker Lindh, a controversial move that West feared would derail his political ambitions and helped delay his nomination to the department for three months in 2009.
He helped negotiate a 20-year sentence for Lindh, an American citizen who was 21 years old when he was captured in Afghanistan in 2001. Under the deal, Lindh avoided a life sentence by pleading guilty to serving in the Taliban army and carrying weapons, and the government dropped its most serious charges, including conspiracy to kill Americans and engaging in terrorism.
Now West will lead the U.S. effort to block Arizona's immigration law from its July 29 implementation. The law makes it a crime to be in the state without immigration papers and requires police to determine whether suspects are in the country legally -- a provision that critics say will promote racial profiling and is unconstitutional.
In the lawsuit, the Justice Department claims the federal government has "preeminent authority" on immigration enforcement and that the Arizona law "disrupts" that balance.