The reasons, I think, there is opposition to the SAVE act, and why I oppose it are the following:

-There is currently no problem with voter fraud in the US, though there is a great furor falsely ginned up that there is.

-These midterm elections may redefine the future of American democracy, or lack thereof going forward.

-Implementation of this hurriedly crafted bill by the president and his party likely contains several Trojan horses that will only become (more)apparent in the manner of its enforcement. Don't forget, Trump still refuses to accept the results of 2020. (And fomented a riot/rebellion for which he has not been called to account.)

Suspicion that Trump is trying to "cheat" the midterms given the abject failure and atrocious outcomes of his policies so far, and his dishonorable track record in business and golf, in not unfounded.