"Maybe there are good legal arguments why Kagan need not recuse herself..."

"... but there is no good reason that she shouldn't at least come forward and publicly explain her decision."

Not doing so suggests that there is something deeply political (and maybe, like Bush vs. Gore, even something partisan) going on, and that possibility could negatively infect what many of us on the left hope to be Supreme Court affirmation of the constitutional validity of the Affordable Care Act.

"So far it appears that only Republicans and conservatives want Kagan to recuse herself from hearing the [Obamacare] case..."

"... while liberals and Democrats take the opposing view. I have been a liberal constitutional law professor for more than 20 years, and a loyal Democrat. I believe the Affordable Care Act is constitutional and that it would be truly unfortunate for the country (and the party) if the court strikes it down. I also recognize that there is a much greater chance of the court erroneously striking down the PPACA if Kagan recuses herself. That said, I believe that as a matter of both principle and law, Kagan should not hear the case."

Eric Segall in Slate.