As you may have heard, Dem leaders are refusing to say whether their appointees to the congressional “super-committee” should draw a hard line on entitlements and taxes. In fact, they’re actually suggesting that they think telegraphing flexibility at the outset will help them marginalize the GOP — which is already drawing a hard line against any revenue hikes — as uncompromising and extreme.

But a coalition of labor unions and liberal groups is telling Harry Reid and Nancy Pelosi that this isn’t good enough. The Strengthen Social Security Campaign has sent the Dem leaders a letter calling on them to refuse to appoint anyone to the committee who will agree to any Social Security benefit cuts:

Dear Majority Leader Reid and Leader Pelosi:

We thank you for your tireless leadership in support of Social Security and for your efforts to prevent Social Security benefits from being cut in the Budget Control Act of 2011. You are a true champion of the 55 million Americans who depend on Social Security.

On behalf of the Strengthen Social Security Campaign, which is comprised of more than 320 national and state organizations representing more than 50 million Americans from many of the nation’s leading aging, labor, disability, women’s, children, consumer, civil rights and equality organizations, we write to urge that your three appointees to the Joint Select Committee on Budget Deficit Reduction be steadfast supporters of Social Security, who oppose including cuts to the program in any plan to reduce the deficit.

Interestingly, the group’s original draft of the letter was only addressed to Reid, and not Pelosi, because it was deemed more likely that a Reid appointee would give ground on Social Security.

There’s been some debate on the left as to whether it’s necessary to insist that appointees draw a hard line, with some saying it’s unlikely Dems will give any ground on entitlements without any GOP agreement to raise revenue. And I definitely sympathize with Dem leaders here: If all parties signal at the outset that they won’t give ground on core priorities, it’s hard to see how the “super-committee” can get anything done.

But still, it’s hard not to see the obvious contrast that’s taking shape. Dem leaders need to be pressured into signaling a hard line heading into the super-committee talks. But Republicans are volunteering at the outset that it is a matter of GOP policy that they will do this — even though the Standard and Poors downgrade explicitly cited GOP intransigence on tax hikes as a key reason for its decision:

House Majority Leader Eric Cantor told Republican lawmakers to expect — and resist — increased pressure to raise taxes following the downgrade of the U.S. credit rating by Standard and Poor’s.

“Over the next several months, there will be tremendous pressure on Congress to prove that S&P’s analysis of the inability of the political parties to bridge our differences is wrong,” Cantor wrote Monday in a memo to House Republicans. “In short, there will be pressure to compromise on tax increases. We will be told that there is no other way forward. I respectfully disagree.”

Yep — it’s like a rerun of a very bad movie, seen through the haze of a very bad hangover.