I just reviewed this article from WLBT (conceivably a local station?) that was published on election day, while this was happening.

It opens with this:

A member of the Hinds County Republican Executive Committee is considering filing a lawsuit to keep the polls open longer after a number of Hinds County precincts ran out of ballots.

“We’re trying to figure out how to do it,” said committee member Pete Perry. “We’re trying to make sure voters get to vote.”

In direct opposition to what OP claims, the Republicans were fighting to keep the polls open.

Again, still open to conflicting evidence, which support’s OP’s claim.

So far what I can tell is that Democrats dropped the ball, disenfranchised thousands of black voters, and then attempted to blame Republicans for it, after also claiming to take responsibility for the failure.