Let's start with a correct claim:
The fiscal outlook is grimmer than before, therefore we should spend less on health care reform than I used to think.
I'm willing to make a comparable admission when it comes to tax cuts, so will you sign on to this claim about health care and revise your policy prescriptions accordingly? (Unless of course your previous estimate had forecast the current revenue situation; Nouriel Roubini could claim this.)
If you do not sign on to this claim, you are committing the third health care cost fallacy. Note also that your support for non-revenue-intensive means of health care reform might well go up, for related reasons.
Addendum: Megan McArdle offers some related sentences to ponder:
Conversely, if there is some political or institutional barrier which is preventing you from controlling Medicare cost inflation, than that barrier probably is not going away merely because the program covers more people. Indeed, to the extent that seniors themselves are the people blocking change (as they often are), adding more users makes it harder, not easier, to get things done.