From CBS News' John Bentley:
(DEFIANCE, OHIO) -- Joe the Plumber stood up John the Presidential Candidate. At a rally here, McCain asked for Joe Wurzelbacher – aka "Joe the Plumber" – to stand up and be recognized, but he was nowhere to be found.
"Joe's with us today. Joe, where are you?" McCain asked, clearly hoping that Joe would make himself known. "Joe, I thought you were here today. All right, well, you're all Joe the plumber, so all of you stand up."
The official campaign response was that Joe the Plumber is a metaphor – every hard-working American is Joe the Plumber. McCain has held several events called "Joe the Plumber" rallies where Joe was not – and was not expected to be – in attendance. But sources within the campaign have said that Joe was indeed supposed to be here, and that there was some sort of scheduling mix-up that resulted in him not showing up.
Recently, Joe has been campaigning with McCain's running mate Sarah Palin, and the campaign says he will be showing up later today on the Ohio bus tour.