Speaking as an American, it is for me. Even before the 3 U.S. automakers were having their current problems, I have always believed in buying American. And now I believe in buying American more than ever.
The last foreign car I bought was a 1978 Toyota Celica GT, and despite it being a reliable car, it bored me to death within 6 months and I had to get rid of it.
I ordered a new 1980 Z28 4-speed and never looked back. Since then, I've owned nothing but manual transmission, RWD, U.S. cars: 1984 Z28, 1987 Mustang GT, 1995 Mustang GT, and 2005 Mustang GT, and loved all of them.
Not that I wouldn't enjoy a BMW 135i or Nissan 370Z someday, but now is not the time, IMO. And it's not like I'm really sacrificing by buying a new Camaro SS...