It's worth noting that prior to World War II, U.S. citizens used to pledge to the American flag in a similar "Roman" or "Seig Heil" position of the arm. To eliminate any similarity to the Nazi salute, the position was changed to the right hand over the heart.
Which ties in nicely with my point.
You don't see conservatives tryng to argue we should keep the Roman salute for the Pledge. Instead, we recognize that the iconography has been irretrievably co-opted by the Nazis and, therefore, we salute the flag differently.
A valid argument can be made about the Confederate Flag as well.
