Originally Posted by
scottishbride
why do I get the feeling that the DHS is trying to find a way to make
every US citizen carry papers at all times? (like the former USSR or
most countries in the EU today)
also, by setting up interior immigration-status checkpoints, isn't the
Border Patrol basically admitting that they have already failed to secure
the physical US/Canada/Mexico border in the first place? 
Your post somewhat lacks historical context. These internal checkpoints were established more than 40 years ago, long before the DHS and the current immigration hysteria. So, the answer to your question is "yes, they are admitting that they can't secure the borders." Has anyone said otherwise, in the last 50 years?