Here’s a paper (in an academic site) about the effort to constitutionalize the right to vote. Creating a constitutional right to vote would wipe out rules against felon voting in prison, wipe about voter ID, potentially wipe out precincts, advance voter registration, and create meddlesome tinkering with district lines. That, of course, means that the people in favor of voting in prison, opposed to voter ID, against voter registration and forever looking to tinker with district lines are naturally the forces behind the federal constitutional right to vote.
Voting free from race and gender discrimination is already a federal constitutional right. The general right to vote is not in the text of the constitution. That’s what allows states to place reasonable voting regulations in place like advance voter registration, precincts, and other residency and citizenship requirements. It would give rise to potential lawsuits that would allow the slightest barrier to voting to be struck down – such as being in prison for felony voter fraud.