So the Preamble is the Law of the Land, now?
Until you do something about it, Roe v. Wade is still the Law, and abortion will remain legal.
You would be laughed out of court and you would be no better than Obama ruling by decree.
While you’re right about ruling by decree you’re off in left field somewhere with the preamble attack. Read the 5th and 14th amendments. If Congress passes a law defining persons to include the unborn Roe is void and unborn children are protected under the 5th and 14th Amendments. Even Blackmun understood this simple logic.