Looking at the numbers I'd classify this as a "fart in a whirlwind" approach. Sure they are sending more feds down, but to be honest given the length of the Texas Border alone they are still going to be pretty much concentrated in the Port of Entry areas.
If you look at Durbins stance concerning the weapons and the "morale obligation" you can see that he's using this to stump for the assault weapons ban. Ignoring the fact that verified shipments of arms have been tracked coming into Mexico from South and Central America as well as Southeast Asia.
Once again it's politics on the border to adjust domestic politics.
