Eliot Spitzer appeared on last night's "In the Arena" on CNN to present Donald Trump with one of the most pointless challenges yet: Show us a certificate of net worth.

The taunt is in reaction to Trump's demands to see President Barack Obama's birth certificate (Spitzer waved what he said was a photocopy of Obama's certificate of live birth around while he spoke) and Trump's bragging about his enormous wealth, but what difference would it really make if Trump disclosed exactly how much he was worth? (Not to mention, a net-worth certificate seems to be old-school bank insurance of some sort.)

"I respect him, I like him, disagree with everything he says about politics these days, but this guy has built buildings," Spitzer said of Trump. "He's good for New York City, and if there's a little bit of bravado in there, that's also what New York is all about."

Watch the video, which originally broadcast on CNN's "In the Arena" on April 18, 2011, below.