“An accountant complains that every time the government shifts to the left, the decimal points in the national debt move to the right,” is cited in print since at least 1950. The saying was a favorite of Ronald Reagan (1911-2004).
 
 
26 September 1950, Burlington (IA) Hawk-Eye Gazette, “Nuggets from Other Brains,” pg. 4, col. 3:
An accountant complains that every time the government shifts to the left, the decimal points in the national debt move to the right.—Oskaloosa Herald.
     
Google Books
American Opinion
Volume 14, Issue 2
1971
Pg. 312:
Every time the government shifts to the Left the decimal point in the national debt moves to the right.
   
30 November 1972, Mountain Democrat (Placerville, CA), “Words and Music,” pg. 18, col. 1:
Every dawgone time the government shifts a little to the left, the decimal point in taxes and national debt shifts to the right.
 
Google Books
Iron and Steel Engineer
Volume 50
1973
Pg. 11:
Every time the government shifts a little to the left, the decimal point in taxes and the national debt shifts to the right.
   
Google Books
The Notes:
Ronald Reagan’s Private Collection of Stories and Wisdom
By Ronald Reagan
Edited by Douglas Brinkley
New York, NY: HarperCollins
2011
Pg. 192 and Back Cover:
Every time the gvt. shifts to the left the decimal point in taxes shifts to the right.