(FORTUNE Magazine) – When AARP threw its weight behind the $400 billion Republican-led Medicare prescription-drug bill now headed for a vote in Congress, plenty of Americans had one response: Huh?!? Many seniors who see the coverage as inadequate are especially angry (yes, those would be the same seniors cutting up their AARP cards on TV). FORTUNE's Ellen Florian caught up with AARP CEO Bill Novelli for some answers.

Q: Why is AARP endorsing a bill it has publicly called "far from perfect"?

A: We can't afford to wait for perfect. In this Congress, perfect isn't going to come.

Q: Still, your critics are accusing you of selling out seniors. Are you?

A: Actually, we're doing the exact opposite. These critics say that this is going to bring the downfall of Medicare. AARP champions Medicare. We would never do anything to harm it.

Q: So why is Ted Kennedy attacking the bill?

A: The truth of the matter is, I'm not sure. I have tremendous respect for Ted Kennedy, and he wants Medicare legislation. He wants drug coverage. I thought that he would support this bill, and maybe he still will.

Q: Are you worried about long-term fallout with the Democrats?

A: Yes. When this is over, we're going to have to mend some fences. We're a nonpartisan organization, but we see these people as our once and future friends.

Q: What about fallout with your members?

A: We are getting a lot of negative response from our members. But when they understand that this isn't going to jeopardize Medicare, I think this criticism is going to be nullified.