[Hmm, might want to explain that to the US Department of Justice, Civil Rights Division and their over sight on the Voting Rights Act, the National Voters Registration Act, the Helping Americans Vote Act to mention a few. ]
Completely unnecessary.  I'm sure they are aware of the differences between Constitutional provisions and federal law.
[various sections of the voting and elections acts]
The what?  The "acts" as is in federal legislation?
[the 19th amendment of the Constitution ... wasn't really needed in order for women to vote in federal elections ?]
Yes.  Just like Prohibition didn't need to be the 18th.  They could have been accomplished by fed. regs as well.  The big diff (and why enshrine) is that Amendments are harder to repeal/amend aka "top shelf" legislation.
[Federal regulation of voting comes from laws enacted by Congress that are Constitutional.]
Enlighten me where is there an enumerated power in the Constitution about Congressional voting regulatory power?