It was clear yesterday that if liberals in the Senate were going to support a plan to toss out a public option in lieu of a network of nationally-based, non-profit plans regulated by the Office of Personnel Management (OPM), they were going to have to get something in return. While negotiations are still ongoing, Senate progressives seem most interested in a proposal that would expand access to Medicare, the nation's single-payer health insurance plan for those over 65.  The Wall Street Journal summarizes:

Negotiators Monday were considering a proposal that would open Medicare to people ages 55 to 64 if they couldn't find coverage elsewhere. The proposal would allow them to buy insurance coverage at subsidized rates under Medicare, though the subsidies wouldn't be as great as those for people 65 and over, said congressional aides and lawmakers.

To be clear: Under this plan, one could purchase Medicare coverage through the health insurance exchanges, meaning the pool would only include those that lack access to group insurance or work for a small employer and are not eligible for other government programs. And because the exchanges wouldn't become operational until 2014, those eligible would, at least as currently envisioned, have to wait to about four years to join.

Even so, some reformers think the plan has a lot of promise. For one thing, older people looking for coverage on the individual market -- because of higher rates of disease -- are just the type of patients insurance companies try to avoid. Medicare negotiates lower rates than private insurers and spends less on administration, meaning premiums would likely be cheaper, as well.

Some progressives, however, aren't yet convinced that the OPM alternative for those under 55 is strong enough. “It’s important to understand that [the proposal] would be a completely private plan,” Illinois Rep. Jan Schakowsky told Greg Sargent yesterday. “Right now, I don’t see it as a good deal.” Their frustration could become crucial if officials in the Senate decide to use a procedural move known as "ping-ponging." The Huffington Post's Ryan Grim has the scoop:

There is increased chatter on Capitol Hill about a possible "ping-ponging" of the Senate health care bill: that chamber would pass its health care bill, send it to the House and the House would be asked to pass it with no changes and send it directly to the president.

That limits the options of congressional critics -- under the usual procedure, lawmakers dissatisfied with the bill pushed through their chamber can win changes through adroit political maneuvering in conference committee negotiations.

David Waldman explained the maneuver over at DailyKos, as well. As you can imagine,  Schakowsky is not real happy about the possibility that she and her colleagues would be locked out of final negotiations. "The House intends to negotiate with the Senate," she told Sargent. "We expect those deliberations to be vigorous. The House is not simply going to sign on the dotted line."