I think its a huge political mistake for the republican party to promise pro-life people - that overturning Roe means that abortion will be outlawed in all 50 states, in all cases, even for adult women in the first trimester.
shift the debate to that - and you will lose independent women voters in droves.
if you can bound the argument to restrictions on late term, parental consent, and having it return to the states where voters and their legislatures can decide for themselves - its a net win politically. but a sweeping federal ban, is not.
I (finally) agree with you - I think it is clear Scalia would not impose a federal ban on all abortions - I doubt Chief Justice Roberts would either.