Barack and Paul Volcker and three governors and small business owners and Google CEO are line in Florida.
Watch them online now at cnn live video.
Amid concern that battleground states were slipping from their grasp, Mr McCain's aides scheduled a daylong tour on Tuesday across Pennsylvania - one of the only Democratic-leaning states where the Republican ticket is still aggressively campaigning in hopes of scratching out a comeback victory.
The subject of the battered economy is particularly timely in Florida, which has unemployment above the national average and one of the worst foreclosure rates.
So, on a two-day swing aimed at turning Florida his way, Mr Obama planned to hammer home the message that he has the best economic plan during Tuesday's round-table.
The event, amounting to a mass public endorsement of his economic proposals, was drawing the governors of Michigan, Ohio, New Mexico and Colorado to the town of Lake Worth on Florida's east coast.
All the states except Michigan, which Republican John McCain recently abandoned, voted for President George W. Bush in 2004. But polls show Obama leading in all four states, which now have Democratic governors.
In Colorado and Ohio, Mr McCain is believed to be down, but within or close to the margin of error in polls. Florida, once solidly in Mr McCain's corner, now is a tossup. And in New Mexico, Mr Obama appears to have a comfortable lead.
Also participating in the discussion are Google Chairman and CEO Eric Schmidt and former Federal Reserve Chairman Paul Volcker, a Mr Obama campaign adviser.