Tires: tire wear, sierra 4x4, alignment problem

Question
I own a 2005 gmc sierra 4x4 crew cab with maybe 19000 miles.  maybe a 1000 miles or less pulling some sort of trailer.  The problem is inside tire wear on the front.  I had it realinged with about 12000 miles and it doesn't seemed to have helped.  These are factory tires.  What could be wrong with this?  Do I need to talk with someone at GM?  Thanks

Answer
Landon,

This is an alignment problem, but the problem might be that the trailer is causing the front end to lift, changing the alignment when pulling the trailer.

But also be aware that if you HAD a problem with the alignment and that was fixed, you didn't fix the symptom (tire wear) unless you changed tires, so factor that into your equation.