"If the last debt ceiling discussion was playing with fire, this time they're playing with nitroglycerin," Honeywell CEO David Cote told CNBC. But as a benefactor of lower taxes, he did not offer any specifics on what policies he and other CEOs would get behind or oppose.

The president also met with progressive and labor leaders earlier in the week who are aggressively pursing higher taxes on the wealthy.

"Our millions of members are fired up and ready to go, and are taking the fight to Republicans who are holding middle class taxpayers hostage to win another tax cut for the rich," Moveon.org Executive Director Pedro Morillas.

Advisers to the president are meeting with a coalition of self-described millionaires today, several of whom are prominent Democrats, who are advocating on the side of higher taxes. And Vice President Biden is meeting with a dozen mayors from across the country today whose cities would be impacted by the fiscal cliff.

The first leg of formal negotiations begin tomorrow when House and Senate leaders travel 16 blocks down Pennsylvania Avenue to the White House for a bipartisan meeting.

While Mr. Obama and Boehner publicly stand by their demands, they are both simultaneously offering willingness to negotiate.

"There's all kind of information and data, but getting into specifics of that at this point would not be conducive to trying to get an agreement with the White House," Boehner told reporters Wednesday.

"This is just a matter of whether or not we come together and go ahead and say Democrats and Republicans, we're both gonna hold hands and do what's right for the American people, and I hope that's what happens," the president said.