You can also switch in the sign for stupid.
I just use my dominant hand to sign the letter "R" and shake it a little.
I read in my book that for Dem. you just make a "D" and shake it a little bit. and the same for Rep. - Make a "R" and shake it a little.
You need to remember these are done small right in front of the shoulder.
"D" will = "where" if you place it wrong or move too much.