From Michael Linden at the Center for American Progress think tank, a short, well-explained video looking at three sets of hard numbers -- gross domestic product, private sector layoffs, and changes in employment -- from before the recession started in 2008 to the present.
What's clear from all three data series is that the U.S. economy was in really serious trouble by the start of 2009 when the stimulus was passed. Linden doesn't mention it, but a number of economists complained at the time that with the economy as bad as it was, the stimulus was too small to turn things around quickly -- and they turned out to be right.
But what the numbers do show is that these three key measures had been getting rapidly worse and worse before the stimulus, and they abruptly started looking better very soon thereafter.
As Linden takes pains to say, it could have been just a coincidence, but that seems rather unlikely.