Liberal groups have targeted Democratic Senators in a campaign to forestall benefit cuts to social insurance programs as part of any deal to avert the fiscal slope. The groups, which include CREDO, Progressives United, the PCCC, DFA, MoveOn, the Campaign for America’s Future and Rebuild the Dream, have segmented the Senate into three categories, based on calls to Senate offices already made by their members.

“Weak-kneed” members consist of Sens. Kent Conrad (ND), Joe Manchin (WV) and Joe Lieberman (CT). Conrad and Lieberman are both retiring.

The “champions” are: Sen. Daniel Akaka (HI), Sherrod Brown (OH), Ben Cardin (MD), Al Franken (MN), Kirsten Gillibrand (NY), Tom Harkin (IA), Frank Lautenberg (NJ), Patrick Leahy (VT), Carl Levin (MI), Jeff Merkley (OR), Barbara Mikulski (MD), Jack Reed (RI), Jay Rockefeller (WV), Bernie Sanders (VT) and Sheldon Whitehouse (RI).

The rest are what the groups describe as “wavering” or “part-way there.” These are the members whom they intend to apply the most pressure.

The full list: Sens. Max Baucus (MT), Mark Begich (AK), Michael Bennet (CO), Jeff Bingaman (NM), Richard Blumenthal (CT), Barbara Boxer (CA), Maria Cantwell (WA), Tom Carper (DE), Bob Casey (PA), Chris Coons (DE), Dick Durbin (IL), Dianne Feinstein (CA), Kay Hagan (NC), Dan Inouye (HI), Tim Johnson (SD), John Kerry (MA), Amy Klobuchar (MN), Herb Kohl (WI), Mary Landrieu (LA), Claire McCaskill (MO), Robert Menendez (NJ), Patty Murray (WA), Bill Nelson (FL), Ben Nelson (NE), Mark Pryor (AR), Harry Reid (NV), Chuck Schumer (NY), Jeanne Shaheen (NH), Debbie Stabenow (MI), Jon Tester (MT), Mark Udall (CO), Tom Udall (NM), Mark Warner (VA), Jim Webb (VA) and Ron Wyden (OR).

That’s a pretty narrow group of 15 champions in a 53-seat caucus. But it seems accurate to me.

Meanwhile, the President actually brought up the Medicare eligibility age in an interview with ABC News yesterday, and the only real specifics on it that he said was that it doesn’t save much money.

“When you look at the evidence, it’s not clear that it actually saves a lot of money,” he said. “But what I’ve said is let’s look at every avenue, because what is true is we need to strengthen Social Security, we need to strengthen Medicare for future generations, the current path is not sustainable because we’ve got an aging population and health care costs are shooting up so quickly.”

It’s definitely true that raising the eligibility age isn’t a big money-saver; the estimate is about $100 billion over ten years. But it does cut 435,000 seniors off of coverage annually, and the uninsured population is simply at a higher risk of death from lack of coverage. So I don’t support “looking at every avenue” when one of them amounts to murder by spreadsheet.

The eligibility age has been batted around like a piñata at this point, and it’s clear that the President and Democrats in Congress would pay a heavy price for agreeing to that in negotiations. But it could represent the shiny object that attracts the most debate, while some other benefit cut gets contemplated in relative comfort.