Even as some fellow Democrats are calling a public insurance option all but dead, liberal House Democratic leaders are claiming new momentum for the provision, their top priority in the health care debate. Rep. Raúl Grijalva (D-Ariz.), co-chairman of the Congressional Progressive Caucus, said Thursday that after a bruising August of misinformation about the plan, “the reality has hit home that the public option— is the only way to achieve meaningful reform. Rep. Keith Ellison (D-Minn.), another leader of the liberal bloc, said the group has more than 60 lawmakers ready to oppose a package that does not include such a plan. “We mean it for the House floor and we mean it for when the bill comes back from conference,— Ellison said. “We’ve got 60 people and we’re not going to back down.—The left wing of the party is hoping a strong rally by liberals in the House will help shore up prospects for the public option, which has become the target of a noisy, late-summer assault by critics of the plan. The White House appeared to try to redirect the debate over the weekend, when President Barack Obama called the public insurance option a sliver of a larger effort and Health and Human Services Secretary Kathleen Sebelius said it was not essential to reform and that Obama would be open to nonprofit medical cooperatives instead. But the resulting outcry from liberals prompted the administration to back off.Ellison said the comments from White House officials actually helped liberals make their case, since they caused leading Republicans to reveal themselves as cool to cooperatives as an alternative. “We better not count on any Republican votes. That’s the fact,— he said. Nevertheless, the liberal lawmakers acknowledged they have a tough fight ahead. And unlike party moderates, who are practiced at leveraging the threat of their opposition to change policy, liberals are less comfortable driving a hard bargain. “We’re not doing this to be obstructionist or to divide the party or to embarrass the administration,— Grijalva said. “At this point, we haven’t become allies in the strategy, but we’re getting there.—The lawmakers made their remarks on a conference call to tout a report by the Institute for America’s Future that argued the co-op approach emerging from the Senate Finance Committee is an “ugly— alternative to the public option. Progressives trying to protect the public plan have the backing of Speaker Nancy Pelosi (D-Calif.), herself a former member of their caucus. In a Monday statement, she reaffirmed her support for the public insurance option. And on a Tuesday teleconference with the Democratic Caucus, she sought to reassure her Members that the White House was likewise committed to the approach, people on the call said. “After the Sunday morning talk shows, our leadership reached out to members of the administration,— said Rep. Tammy Baldwin (D-Wis.), who told the Caucus on Tuesday that a public program in Wisconsin that has a federal waiver to compete with the Medicare prescription drug benefit has brought down costs while co-ops in the state have not. “Our leadership has been very firm and very committed to a public option, and I feel the same way.—But with battle lines hardening within their ranks, Democratic leaders face a tricky task after the Congressional recess: keeping moderates on board to help pass a House bill that includes the public plan or persuading liberals not to sink a measure with an alternative approach. Leadership aides said they have been closely tracking town hall meetings over the recess and are encouraged that calmer sessions have replaced the raucous ones that rattled lawmakers at the start of the break.But the angry reception appears to have taken its toll.“I think there is a level of anxiety about the public option among moderates,— one leadership aide said. “August has been a tough month.—