Stu Rothenberg: “Midterm elections and presidential cycles have such different dynamics that the two should almost never be discussed together. That will not prevent people from doing so, but they should resist the temptation.”

“Each midterm election tends to be a referendum on the incumbent president, while each presidential election is a choice between nominees.”

“Of course, a presidential re-election contest is something of a referendum on the incumbent, since a sitting officeholder seeking another term will be evaluated on the basis of his performance in addition to what he or she promises for the future.”

“But the existence of an alternative on the ballot makes a presidential year very different from a midterm year. That’s why connecting the dots from the last midterm election to the next presidential contest is so unwise.”