Ask and ye shall receive...
Nixon (4): Bullseye I, Double Bullseye, Double Digits, Mystery Price
Ford (0): (This surprised me)
Carter (4): Professor Price, Finish Line, Shower Game, Telephone Game (not to be mistaken for The Phone Home Game)
Reagan (7): Hurdles, It's Optional, Trader Bob, Walk Of Fame, Balance Game I, On The Nose, Add 'Em Up
Bush 41 (4): Give Or Keep, The Phone Home Game, Bump, Gallery Game
Clinton (4): Super Ball, Super Saver, Split Decision, Fortune Hunter
Bush 43 (9): Poker Game, Penny Ante, Hit Me, Credit Card, Buy Or Sell, Joker, Barker's Markers, Clearance Sale, On The Spot
Obama (1); Step Up
Trump (0)
Four different Presidents had 4 games each retired during their Presidency. Bush 43 with 9 retired somewhat surprised me since those were more recent years (2001-2009). 7 under Reagan didn't surprise me as much since he too was in office for eight years.
As an added bonus, as I am a novice history nerd when it comes to the U.S. Presidents....Clinton, Bush 43 and Obama were only the second group of three consecutive Presidents whose terms all lasted exactly 8 years. The only other time that ever happened was from 1801 - 1825 with Thomas Jefferson, James Madison and James Monroe.