The Constitution of the United States Article 1, Sec. 1

Article. I.

Section. 1.

All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.

Note what it doesn’t say: it doesn’t say that the President can legislate; it doesn’t say that the Supreme Court can legislate; it doesn’t say that activist or even non-activist judges can legislate. Legislation belongs exclusively to two bodies of government: the House of Representatives and the Senate.