Vice President Biden's sharp retort to Rep. Paul Ryan's invocation of President John F. Kennedy was by far the single biggest single moment of the debate according to Twitter metrics.
"Oh, now you're Jack Kennedy?" Biden quipped when Ryan asserted that Kennedy had successfully lowered taxes to foster economic growth.
After Biden's retort, Twitter erupted with 58,275 tweets per minute, more than at any other point in the debate.
Biden's comments brought to mind the other famous Jack Kennedy debate moment in which Democratic vice presidential candidate Lloyd Bentsen slammed his Republican opponent Dan Quayle for comparing himself to Jack Kennedy with the retort: "Jack Kennedy was a friend of mine. Senator, you're no Jack Kennedy."
Thursday's debate was in essence a Lloyd Bentsen moment for tax and budget wonks.
Ryan was right that Kennedy advocated lowering taxes, but it may have been Ryan's appropriation of Kennedy's legacy that stung Democrats.
"There is this tremendous love for Jack Kennedy for reasons hard to explain," said Alan Brinkley, a Columbia University American History professor who has written a book about Kennedy. "But Democrats still believe that Jack Kennedy is their great messiah and so I think that's what made so many Democrats angry."
On the tax policy, at least, Ryan was mostly right.
Kennedy did propose lowering taxes early on in his administration, a step he said was necessary to bring the country out of an economic recession.
"If we are to prevail in the long run, we must expand the long-run strength of our economy. We must move along the path to a higher rate of growth and full employment," Kennedy said in his 1963 State of the Union address. "To achieve these greater gains, one step, above all, is essential--the enactment this year of a substantial reduction and revision in Federal income taxes."
But Ryan left out a few important details. In 1960, the top income tax rate was closer to 91 percent than the 35 percent rate it is now, according to the non-partisan Tax Policy Center.
And Kennedy was assassinated before tax cuts were approved by Congress in 1964 during President Lyndon B. Johnson's administration. When they were approved, the top rate dropped from 91 percent to 77 percent in 1964.
"I think what made this such a to-do is that the taxation was drastically different in the 1960s when the top taxation was something around 70 percent and at some point at 90 percent," said Brinkley. "The 'Kennedy tax cut' was within a much higher tax world."
And economic growth had already started improving before the cuts went into place. The economy was growing at a breakneck pace of 6.1 percent in 1962, it slowed to 4.4 percent in 1963 and picked up momentum again to 5.8 percent in 1964 and continued growing until 1966.
But neither Ryan nor the offended Biden elaborated on the relevance of the "Kennedy tax cut" to the current economy.
"It's complicated because it depends on what an economy looks like. There are times when cutting taxes does help the economy and there are also times when cutting taxes creates more debt and much more danger," said Brinkley. "This is an issue that you can't explain easily in a debate."