What's is new mexican chile powder ingredient for the Shrimp with Red Chilie and Pine Nuts

I think California chile powder and Guajillo chile powder would both be better than ancho, which is darker and smokier. But it will do in a pinch.

... and what it is not, is a blend of chiles and herbs (and sometimes salt) that is sold as chili powder. For those of us who live where chiles/chilis are a foreign (New England), there's a learning curve with stumbles along the way.

New Mexico, or Hatch, chiles are just a specific kind of chili. You can grind the dried chiles to make your own chili powder, but if you can't find them, ancho chili powder would be a decent substitute.