Obama's Health Care Reformist

Dr. Ezekiel "Zeke" Emanuel, special health adviser to the president's budget director, has emerged as a key behind-the-scenes player for what could be the biggest overhaul of the nation's health care system in the past two decades.

With lawmakers working in earnest this week to craft health care legislation, Emanuel admits he often thinks about what could go wrong.

"What scares me is we get it wrong and we don't create something that's going to be sustainable, that has some major defects in it," Emanuel said recently in an exclusive interview with ABC News. "Establishing an exchange that is unstable, creating a more Byzantine bureaucracy, not actually ending up getting costs under control and just fueling health care inflation. Those things would be disastrous."

Even worse, Emanuel said, would be to do nothing about a health care system he calls 'unsustainable" and "really, really dangerous."

Eldest Emanuel Brother Steps Into Spotlight

Emanuel is the eldest brother of White House chief of staff Rahm Emanuel, 49, and Hollywood talent agent Ari Emanuel,48, no strangers to the media spotlight.

But when Zeke Emanuel, 51, was tapped by the Obama administration to be special health adviser to budget director Peter Orszag in February, the renowned medical ethicist, oncologist and policy wonk became the go-to guy for stakeholders who want a say in the Obama administration's effort to reform the nation's health care system.

He works closely with Orszag and Nancy-Ann DeParle, director of the White House Office of Health Reform, who is coordinating legislative efforts on Capitol Hill.

When the president held a White House meeting last month with the major health care players -- including many of the people who had worked to scuttle former President Bill Clinton's reform efforts -- medical establishment representatives rushed up to Emanuel afterwards to remind him how they knew him.

It doesn't hurt that he also has the ear of his chief of staff brother.

"Working with Rahm is great," Emanuel said. "He can tell me directly, unlike anyone else, when I screw up and when I'm being stupid. And also he knows he can ask me questions he can't ask everyone and get an unvarnished answer."