The news this morning is, quite simply, catastrophic for the president. Economic growth in the second quarter slowed to 1.5 percent annualized from 2 percent in the first quarter. The economy is weakening as the election approaches. No one has ever won reelection in such circumstances. No one. (Harry Truman: 4.4 percent growth in Q2, 1948. Ike: 2 percent growth in 1956 Q2 after negative growth in Q1. Nixon, Q2, 1972: 5.3 percent. Clinton: 3.5 percent. GW Bush: 3.4 percent.)

Granted, things aren’t as bad for Obama as they were for Jimmy Carter; in the second quarter of 1980, the economy actually contracted by .7 percent. But in 1936, Franklin Roosevelt won a landslide despite the Great Depression; as Amity Shlaes noted yesterday on Twitter, annual GDP growth from 1933-1936 had averaged 9 percent. Nine percent.

Perhaps the most interesting analogy is to 1992—a year in which the economy was actually staging a recovery from a recession in 1991. That was, you’ll recall, the year of “it’s the economy, stupid.” The annual growth rate in 1992: 3.4 percent. The incumbent president received 38 percent of the vote that year.

Prior results are no guarantee of future returns, of course. But this all gets to the central problem for the president: What case can he make for a second term with undecided voters?