As opposed to what? NOT extraditing him, after we know he's in custody in Mexico? It has long been accepted practice to agree not to seek the death penalty when we extradite a criminal from Mexico. I can't imagine how NOT agreeing to this -- and thus leaving the guy in Mexico -- would be better for the adminisitration.
Because too much dirt will be made public (and government workers forced to testify) if it goes to trial. I predict Holder will insist on leaving the death penalty option open, just to force a Mexican standoff (sorry) to avoid a trial while giving the appearance of being tough.