"I will violate the pledge, long story short, for the good of the country, only if Democrats will do entitlement reform," Graham said Sunday, referring to anti-tax advocate Grover Norquist's pledge that many Republicans have signed vowing not to raise taxes.

As Graham pointed out, many Democrats are skeptical about changes to entitlements, distrusting of Republicans who they think want to dismantle the programs. Durbin, meanwhile, said Sunday that he is open to some changes to Medicare and Medicaid that prolong the programs but that Social Security should not be part of the discussion.

"Social Security - set [it] aside. It doesn't add to the deficit," he said. Social Security is viable for another 21 years before retirees would see a reduction in benefits.

Thus the major battle lines are drawn in the "fiscal cliff" debate. And outside groups are working very hard to ensure those battle lines are not crossed.

Labor unions have launched a massive lobbying campaign to press their messages. Union leaders from around the country are traveling to Washington this week to meet with lawmakers on both sides of the aisle.

AFL-CIO spokesperson Jeff Hauser says they have two messages: "Not a single day more of the Bush tax cuts for the two percent" and protect Social Security, Medicare and Medicaid. And a coalition of other unions - the American Federation of State, County and Municipal Employees, the Service Employees International Union and the National Education Association have launched TV ads to put pressure on members of Congress to raise taxes on the wealthy and keep entitlements off the table.

The advertising campaign is targeting moderate Democrats - Sens. Michael Bennett and Mark Udall of Colorado, Sens. Mark Warner and Jim Webb of Virginia and Sen. Claire McCaskill of Missouri - who have indicated a willingness to change entitlements.

Another major player in the fiscal cliff talks is the Campaign to Fix the Debt. The bipartisan organization is chaired by former chief of staff to President Bill Clinton, Erskine Bowles, former Sens. Alan Simpson, R-Wyo., and Judd Gregg, R-N.H., and former Gov. Ed Rendell, D-Pa., and has created a coalition of business executives to pressure Washington politicians to avert the "fiscal cliff." For a grassroots component to the coalition, the organization has launched on online petition that now has more than 300,000 signatures.

But Campaign to Fix the Debt's real heft comes from powerful CEOs of major corporations, including Xerox, Honeywell, GE, that have met with Mr. Obama and have been vocal in the media. They are pushing a bipartisan approach and though they're vague about their positions, the main components of the general framework is similar to what Republicans are saying: simplifying the tax code through reform - not raising rate rates - and entitlement reform. Invoking terms used by Democrats, the coalition insists that those relying on the safety net must be protected and reductions to the federal budget can't be implemented too quickly.

The group is running ads in local newspapers and online in 17 states and business leaders and supporters of the coalition are traveling to Washington on Wednesday to meet with members of Congress to push their message.