God might also bless foreigners if they're in America, and those anchor blessees could bring the blessing back to their own countries, diluting America's blessing!
By specifying "Americans" (meaning US Americans, not Canadians or Mexicans or those other people south of Texas), the sticker owner can feel confident God will not bless those undeserving of Americans' blessing.
And, it's the logical opposite of "God damn foreigners!"
With mashed potatoes and gravy. From Tunxis Community College's Corner Cafe in Farmington, CT.
I couldn't finish it. I really, really wanted to, but when you really, really want to finish what's on your plate, that's when you're really finished.