First, the 24th amendment provides that the right to vote [in federal elections] shall not be denied for "failure to pay any poll tax or other tax." Producing government ID is readily distinguishable.

Second, if the 24th amendment was such a great argument for overturning the Indiana statute why didn't the numerous liberals filing amicus breifs raise it front and center?

The Plaintiffs themselves made no 24th Amendment claim. The closest they came was inside their 14th Amendment claim, by making the statement that the ID requirement is "akin to" a poll tax.

They realized full well that it is not a tax.