Kathryn Jean Lopez at NRO shows us a little history.
Writing about the 29,000 who showed up for Oprah-Obama yesterday, the New York Times Caucus blog asks "JFK drew about 35,000 for a Labor Day rally in 1960; get to work, Caucus readers, and tell us if you know of a bigger campaign rally without an incumbent president." There was one bigger than Oprah and JFK and you can ask Rush Limbaugh or Bill Bennett about it. They were headliners for a picnic rally for John Carlson for governor in 2000. The crowd was an estimated 40,000.
Now that poses the question...will Oprah's support help Obama that much in the long run?