Opinions of the Justices

*1202The order also indicates that grave doubt exists as to the constitutionality of the bill, if enacted into law, and requests our opinion on this question:

“Does the statutory presumption established by [Senate No. 2021] or the resulting shifting of the burden of proof violate the Due Process Clause of the Fourteenth Amendment to the United States Constitution or Article 10 of the Massachusetts Declaration of Rights by impermissibly shifting to the challenged parent the burden of proof relative to custody of a child?”

Senate No. 2021 would amend G. L. c. 208, 209, 209A, and 209C. The portion of…