While I roughly agree with Josh Marshall, it should be pointed out that by the standard he uses none of the major candidates have paid the price of admission. Their failure to raise their hands when asked if Dean was "electable," and Kerry's and Lieberman's regular return back to the issue of Dean's "electability" all make the case that people who would support them wouldn't vote for Dean.
As far as I know, Dean is the only one who keeps getting asked this basic question. He has said he wouldn't run as a 3rd party candidate and he has said that he would support the nominee whoever it was. While I wrote yesterday that I didn't like what Dean had said, it's also the case that the other candidates thus far have failed to communicate this basic minimum degree of unity.
It's actually a much more interesting question to ask of the non-frontrunners than the frontrunner. Maybe it's been asked, but I missed it.
...to be clear, it's a stupid Heather gotcha question, but if it's going to be asked...