Why would Christian conservatives in good conscience go to the polls on December 12 and vote for Judge Roy Moore, despite the charges of sexual misconduct with teenagers leveled against him?
Answer: That Alabama Senate race could determine whether Roe v. Wade is overturned.
Of the seven justices who voted for the Roe side of Roe v. Wade, five (Burger, Brennan, Stewart, Powell and Blackmun) were Republicans. Of the two who dissented, one (Rehnquist) was a Republican. The majority opinion was written by Blackmun, not by a Democrat. Or, to put it a different way, if every Democrat on the court had voted for the Wade side, Republicans would still have decided the case in favor of Roe.
Supreme Courts, including Supreme Courts with Republican majorities, have upheld Roe for nearly half a century.
Even if Moore is elected, and even if the Senate doesn't expel or refuse to seat him, and even if his victory doesn't cost the GOP at least one Senate seat and possibly more, and even if a Supreme Court seat comes open during his tenure in the Senate, and even if whoever is president during that time nominates an anti-Roe judge for the seat, the likelihood of Moore being the deciding vote in favor of that nominee is so tiny as to be of no significance whatsoever.
Buchanan has it exactly backward. The purpose of promoting people like Moore for election to the US Senate isn't to overturn Roe. The purpose of yammering about overturning Roe is to promote the election of people like Moore to the US Senate.