Abortion was never "legalized" federally in US. It was just a provisional jurisprudence established by SCOTUS in the 1970s that went on until Congress decides to legislate about it(which would never happened).

That's why fundamentalist Christians spent the last 50 years trying to reconfigure SCOTUS seats to get an anti-abortion simple majority to reverse their previous ruling, but always failing as there needed to be at least 2 consecutive Republican presidents for this to happen.

There was also the justice Ginsburg factor. Her vote was what kept the right to abortion federal until Trump nominated a devout Catholic to succeed her in 2020.

Fanatics both Left and Right wingers consider flawed the method for which SCOTUS members are chosen. Left-wingers oppose because it allowed Trump to chose while Right-wingers oppose because it allowed Obama and Biden to choose. But it is a minority that believes the indication shouldn't be done by The Presidency. They just oppose specific presidents having power to indicate justices.