Washington Post: “In surveys, focus groups and interviews, some voters are expressing doubts that the presumptive nominees will in fact be the nominees. In a Monmouth University national poll conducted last month, almost half of voters said it was ‘very’ or ‘somewhat’ likely that Biden would be replaced as the Democratic nominee by November, and about a third said the same of Trump.
”“An Economist/YouGov survey taken as both candidates clinched their nominations found 33 percent of Americans thought a Biden-Trump rematch would ‘definitely’ happen, 44 percent said it would probably happen, and the rest were less certain.”