if Leftists had voted for Hillary in 2016 abortion would still be legal.

So, this really isn't true in any meaningful way. People like to make a big deal out of the 12% of Bernie voters who went for Trump, but the majority of them identified as conservatives or centrists, while only 18% identified as liberal or left-leaning. Likewise, a lack of turnout doesn't seem to be the issue; black voter turnout dropped, but not by an unexpected margin, and young voters (who tend to be more left-leaning) had very strong turnout. Finally, you could try to blame leftists who voted third-party, but analysis shows that even if every single Jill Stien voter had gone to Clinton, she still would have needed to win over 50% of Gary Johnson's voters (who were obviously unlikely to consider themselves leftists).

You might be able to get the numbers to work if you say that if every leftist who stayed home OR voted third-party OR went to Trump voted for Clinton she'd have won, but that's incredibly hard to prove and probably relies on some specious assumptions (for example, that every Green Party voter was a disgruntled Democrat). At that point, you're pulling so many different groups together under a single banner that it's basically meaningless. You might as well say if women had voted for Hillary abortion would be legal.