Estimate the percentage of GOP voters who'd vote Dem if it weren't for abortion.

[🦀🎂🦀🎂]

the thing is most "single issue voters" tend to pick up all associated views via osmosis anyway. You may join the GOP because of abortion, but that means you stay in the orbit of conservative media and politicians, so you end up picking up right-wing views on everything else*; although if the issue were to disappear it would be a major blow to the GOP cadre - it's a big GOTV issue that gets at the heartstrings of its devotees like few other issues.

* this also explains the tendency for people who have changed parties either way due to Trump to sort of careen off ideologically into their new party - you start listening to pro- or anti-Trump media to match your beliefs around the man and you end up changing your views as well.