Donald Trump never liked the nickname.  Back when he was a New Yorker and a newly minted Republican and generally considered a political oddity, Jeb Bush branded him on live television. According to the former Florida governor, Trump was “the chaos candidate.”

It fit then, and it still fits now: The first Trump vs. Biden debate marked the return of the chaos candidacy.

Though no one who knew him well expected Trump to change because of a trifling factor such as living in the White House for nearly four years, the incumbent president was in classic form Tuesday night. For 98 minutes, he belittled and bullied and berated both his opponent and the moderator — so much so that he made the debate painful to watch. But what was roundly condemned may have been the plan.

Trump trails former vice president Joe Biden in the RealClearPolitics national polling average by 6.1 percentage points. Figuring he needed a strong showing to close the gap, the campaign studied every Biden debate since 1972. The strategy they came up with entailed having Trump  rely on his improv ability rather than employ a structured game plan.

There were just a handful of goals for Trump, a source familiar with the debate prep told RCP:

Knock Biden off his talking points by answering questions from moderator Chris Wallace of Fox News and then posing another one to his opponent. Force him to own up to the less popular parts of his own record. Push the centrist Democrat to own the policy agenda of those on his left flank.