During his town hall meeting at AARP headquarters, President Obama mainly worked to build support for the overall reform effort by warning seniors that inaction could threaten the Medicare program.

"We all know that right now, we've got a problem that threatens Medicare and our entire health care system, and that is the spiraling cost of health care in America today," he said. "As costs balloon, so does Medicare's budget. And unless we act, within a decade -- within a decade -- the Medicare trust fund will be in the red."

But Obama also again argued in favor of a public option, as the Senate Finance Committee is reportedly ready to dump it.

"This is controversial, and I understand some people are worried about this," he conceded. But, "we do think that it makes sense to have a public option alongside the private option. ... I think that helps keep the insurance companies honest because now they have somebody to compete with." He also denied that it would be a Canada-style, "socialized" plan.

And yet, at today's White House press briefing Robert Gibbs seemed reluctant to weigh in as to whether a plan for health care co-ops in lieu of a public option would be acceptable to the White House.

"I know the president's test is, do we have adequate choice and competition for private insurance?" he said, later adding: "Without having seen the finance committee bill, it's hard for us to come down and fully evaluate it."

Gibbs did deny the notion that Obama would be happy to sign any reform bill at this point, saying "that could not be farther from the truth."