ABC News’ Rick Klein reports: Neera Tanden has had a front-row seat for two grand efforts to remake the nation’s health care system: First as an original member of “Hillaryland” in the Clinton effort to overhaul health care in 1993-94, and more recently as an Obama administration senior adviser on health reform. Tanden, who left the administration last month to become chief operating officer of the Center for American Progress, sees the stakes clearly this time around: “The most important thing is for the Democrats to show leadership,” Tanden said on ABC’s “Top Line” today. “They’ve talked about an issue for a year. They’ve told every American — this is a catastrophe to walk away now, would be to show that we are not capable of governing. And that would be an indictment for this election and elections to come.” “And so I think people can look at the temporary moments, the polls, the legislation is not as popular as it once was, but we have the opportunity and the obligation to explain to the American people why we spent a year of our lives working on this,” Tanden said. “Everyone’s tired of it but we’re close to the finish line. And if we fail now we will not fail for just this election, we will fail for elections to come.” Tanden said of the prospect of passing something that she’s “as optimistic as I have been since Massachusetts,” referring to the January election of Sen. Scott Brown, R-Mass., which ended Democrats’ filibuster-proof majority. Asked the percentage chance that a bill passes, she said: “I’m going with 75.” One of the problems over the past year, Tanden said, was the amount of time consumed by debate over whether the health care bill should include a public option to compete with private insurers — a concept that is now effectively dead. “It wasn’t a central element of anyone’s campaign plan,” she said. “It was an important part [of the president's proposal last year], but it wasn’t the driving force. You know, I think that it became something that liberals could really hold on to. And you know, what’s actually as important if not more important is whether there’s enough subsidy in the bill, whether people can really afford health care.” We asked Tanden about how Secretary of State Hillary Clinton is viewing all of this — and whether Clinton herself ever talks health care with the president. “She’s got a big day job,” Tanden said. “I know that the president and her talk about every issue under the sun. I’m very confident that they’ve talked about health care reform. She’s a brilliant policy wonk on this issue, knows the ins and outs. And I’m sure the White House has used her advice and counsel.” “Is she just as frustrated as everyone else watching this?” Jonathan Karl asked Tanden. “Well I’m not going to speak to her level of frustration on this issue. You know, we’re all a little frustrated,” Tanden said. We also checked in with Lynn Sweet of the Chicago Sun-Times and Politics Daily on the palace intrigue surrounding Chief of Staff Rahm Emanuel and senior White House adviser David Axelrod, plus the latest on the race for President Obama’s old Senate seat in Illinois.