it means deficit spend in economic hard times.
It's a bit more complicated than that, to put it mildly. It means we're trapped by the zero-bound on interest rates and therefore monetary policy is sterilized. Obama isn't responsible for liquidity traps.
It also mean that moves of the financial markets are not described by rational expectations hypotheses and the efficient market hypothesis, but instead by partly rational actors whose collective behavior is not necessarily driving the market towards equilibrium. Those partly-rational actors are sometimes overcome by what we now would call mob mentality, which Keynes referred to as animal spirits.