Explain Like I'm Five

It is very much like jim crow laws.

Both Jim Crow and SAVE force people to get a document - which costs money, time, and availability - to exercise their rights

The SAVE Act puts new requirements on individual voters to prove their citizenship status. The requirements are easy for some people to meet but for others they're very difficult. Required documentation includes things like a birth certificate or passport. Neither of those are free to acquire and they aren't convenient to acquire either. This effectively amounts to a "poll tax" where people have to spend a non-trivial amount of money [and time] to exercise their voting rights.

Jim Crow regulations were slightly more racially biased in that white citizens were often given exceptions for things like poll taxes or literacy tests.

The two cases, however, are quite similar in their intent.

So, we've established that it essentially IS a Jim Crow law, but I.think you're looking more for "Why does anybody support it?"

For the last twenty years or so, MAGA supporters have been told that immigrants are destroying the country, doing all the crime, selling all the drugs, taking all the jobs, and spending all your tax dollars on iPhones and sports cars.

And now, they are illegally voting in elections. To MAGA, it's obvious because they are "normal Americans" and they assume that most Americans agree with them, and that a small percentage of people have fallen for the lies of the media that wants immigrants to take over the country for some reason.

Because the Supreme Court decided racism is over, duh. Roberts ended racism, according to Thomas it never existed.