Catholic reactionaries believe that a fertilized egg is a human being, so they oppose IVF. Protestant reactionaries, on the other hand, are less dogmatic on the issue, and they smell political trouble. As a result, Trump, and even GOP members of the Alabama Legislature, want to change the law to protect IVF.
This is a perfect example of a point I made years ago; Protestant and Catholic reactionaries are not natural allies. They are united in their opposition to the mostly secular status quo, but they don’t really agree on how it should be replaced. Creating a theocracy in America would be harder than they think.