except Dwight Eisenhower, been a fullhead?
How bald are we talking here because many of our (U.K) Prime Ministers have had balding heads. Not totally bald but even current PM David Cammeron flicks his hair back to conceal his thinning hair at the top of his head. The Chancellor - Osborne - has a caeser cut to conceal receding. Tony Blair is very thin and whispy now. Callaghan, Wilson, Heath, Home, McMillan, Churchill, Clement Attlee (a proper NW7), Cecil, Gladstone and Disraeli - all NW3/diffuse thinners or more.
U.S. president is bizarre though - very image orientated.
A balding or bald president won't be elected for the same reason as an atheist president; they're not respected.
Not anymore if Trump wins the elections.lol.
If you look at the candidates from the last 60-70 years, not many bald men even ran for president of the US so it would have been difficult for one to be elected. Prior to that there were plenty of baldies in the office.