Liberal bloggers like Yglesias , Klein and Noon are upset that the public holds what they claim are false beliefs about health care reform. For example Klein:
The poll tested a variety of assertions that were simply wrong -- Was health-care reform likely to include illegal immigrants? ...
Since I believe that health care reform is likely to include illegal immigrants I naturally don't agree that the assertion is simply wrong.
It is clear that this is something liberals would like to include if they thought they could get away with it. Yglesias states as much. So any language purporting to exclude illegals will probably be written by people who don't actually want to exclude illegals. Making it reasonable to doubt how effective it will prove to be.
Additionally even if the language excluding illegals was written by people who actually sincerely wanted to exclude illegals there is a substantial chance it would be overturned by the courts. In the case Phyler v. Doe the US Supreme Court ruled that the state of Texas could not refuse to educate illegal immigrants. It is easy to imagine a similar ruling with respect to health care for illegals.
Finally this assertion is not the sort of unambiguous factual statement that can be fairly characterized as simply right or simply wrong. There is too much room for debate.