Will US check travelers going both ways at the Mexican border

The emerging border security plan will likely increase resources for efforts to keep US firearms out of Mexico.  That's a good idea, but a plan that includes checking outbound travelers may be less valuable than building better cooperation on gun investigations.  At a minimum, we should get strong guarantees that Mexico will conduct its own border checks.  Right now, Mexico doesn't always inspect people entering the country from the US, and it's surely a lot cheaper for them to do that than for us to do so.