The president’s opponents like to say there is only one Mr. Trump, and his advisers like to describe a different one: compassionate in private, they insist; altruistic in nature; brawling only when the task dictates as much.

Too often — and despite his best efforts on Thursday — this latter case has tended to collapse in a hail of misstatement and self-congratulation.

He can resemble a chef with one dish, a golfer with one club in his bag — regardless of what the next stroke might require — and a propensity to blame his caddie for the attendant result.

If voters reject him next month, this will be the chief reason: The 2020 campaign is different, and Mr. Trump is not.