I'm not sure I quite understand your point on shutting down the country to stop terrorism. If terrorists want to plot an attack on American soil, they don't need a green card. Ask the illegals that cross the border or arrive on the gulf coast. We catch what,20-30 percent maybe?

Your using the "just because you waterboard someone you don't prevent all terrorists attacks" to justify it, yet it is the same negative as saying "locking down the country will prevent all terrorist attacks from happening."