Even though I like the picture of Jim, my favorite is of the young girl holding the sign that says, "We all came from another country. We all become Americans." Nicely put. Frames the issue of immigration properly...we aren't against immigration, but for assimilation.
"We ALL came from another country......
We ALL became...RED...WHITE...and BLUE
AMERICANS"
That was my very favorite one too!
Simple, "but straight to the point!