“The whole modern world has divided itself into Conservatives and Progressives. The business of Progressives is to go on making mistakes. The business of the Conservatives is to prevent the mistakes from being corrected.”
-from the Illustrated London News, April 19, 1924
Hopping Hadrian's Wall 
I believe it was Bill Clinton who said, if my memory serves, “Conservatives draw lines that should never be crossed; Liberals cross lines that should never have been drawn.”