Kagen went on to say that the public option is still a possibility because the final legislation will have to go through a conference committee to work out the differences between the House and Senate versions. Though he didn't say so directly, his mention of the conference committee seemed to imply that the public option has a real chance of making it through conference and into the final bill.
I'm not sure why Kagen thinks there is even a remote chance of such an outcome. Prominent progressive blogger Chris Bowers had this to say on the conference committee and the public option:
Conference committee (almost certainly) won’t work. Even if the House passes a public option, which they are highly likely to do, do not expect them to overpower the Senate in conference committee. This is because the Senate will already have voted down adding a public option via amendment, and the White House will have already demonstrated that it isn’t going to demand the public option in the final bill. It wil be difficult to convince them to change their mind by the conference committee.Regardless of whether or not you think the public option is a good idea, Kagen seems to be clueless about the politics of the matter.