The candidates have made it clear that they have staked out unalterable positions on this matter. Biden will enforce the immoral law that made it legal, will for the Little Sisters of the Poor to pay for it, will strip the exemptions against it from everyone except the congregations, and will work to make sure that public funds pay for it. To his credit, he has made this perfectly clear. Trump has also made his stand clear. He is opposed to abortion, desires the law to be ruled unconstitutional, and is working to place pro-life people on the courts. We have a clear choice here.
If the same conditions existed for slavery, I would promote the one who was opposed to slavery -- no matter how legal it had been held to be. But slavery has already been decided. That, of course, does not mean it does not exist. Making something illegal cannot make it disappear. But it removes the sanction of the law, the cover or civic righteousness, and the ability of those to hide their personal accountability behind it. That is why abortion is SO important today.
For all the attention given to LBGTQ+ issues, they are not now on the ballot. Moreover, these issues have a strong and powerful ally in the media, are well bankrolled, and have many popular and public voices on their side (from politics and entertainment, just to name two areas). If you are on the side of LBGTQ+, there is not much for your to fight for -- except changing people's minds -- because the law covers you.
We could go down the list of seamless garment issues that are supposedly the same or equal to abortion and you would find that either they are not on the ballot or they already have the law on their side. But the life issues are right now not only on the ballot but live under the threat of an immoral law. That is why we cannot allow Biden a pass for being personally opposed but publicly supportive of the legal right (which I do not even think is a fair characterization of his position). That is also why, no matter how immoral you may find Trump, he does come down on the correct side of this issue. So I cannot give cover to people who want to equate all kinds of issues and decide that abortion cannot be treated differently. It can and it must.