Poe v. Ullman Question

[Mark Graber]

MR. JUSTICE STEWART's dissent in Poe v. Ullman declared,

"For the reasons so convincingly advanced by both MR. JUSTICE DOUGLAS
and MR. JUSTICE HARLAN, I join them in dissenting from the dismissal of
these appeals. Since the appeals are nonetheless dismissed, my dissent
need go no further. However, in refraining from a discussion of the
constitutional issues, I in no way imply that the ultimate result I
would reach on the merits of these controversies would differ from the
conclusions of my dissenting Brothers."

This seems to be to indicate that, at least in 1960, he thought there
was a constitutional right to birth control.  Do others read this
dissent as I do?  If so, does anyone know why Stewart changed his mind?