In 1992, the question was first asked in January, a few weeks further into the election cycle than is the case for the current poll. At that point, 40% of Americans said there was a candidate running who they thought would make a good president, slightly below the current 48%. The 1992 election is similar in broad respects to the current election, in that it also featured an incumbent president with relatively low approval ratings seeking re-election, with the opposition party having not yet coalesced around a strong front-running challenger.
One manifestation of this displeasure with the presidential field in 1992 was the emergence of third-party candidate Ross Perot, who, despite dropping out and then re-entering the race, ended up with 19% of the popular vote. No such prominent third-party candidate has yet announced his or her candidacy in the current election cycle, but on the basis of this question, it appears the public could be receptive to such an eventuality.