American Presidents.

[AndyRM]

The pipe smoker is definitely Ford - from the artists website:

Republicans (Counterclockwise around the table beginning in lower left): GHW Bush, Lincoln, Ford, Nixon, T. Roosevelt, Eisenhower, GW Bush, Reagan

Lincoln was a republican, so that makes sense to me?

 

[Darius_Jedburgh]

Think that's Eisenhower at the back next to Dubya.

Too late Andy RM beat me to it.