Justice Sotomayor: "too many" states disenfranchise prisoners

In my quick thoughts on oral argument in Evenwel v. Abbott, my read of the PDF transcript missed this exchange, which I picked up listening to the audio this weekend:

MR. CONSOVOY: . . . The State can solve this problem themselves. These States can enfranchise these people and give them the vote. The States come here to say we do not want them to vote, but we want them to count for districting. That should be rejected by this Court.

Second--

JUSTICE SOTOMAYOR: That's not quite accurate. For--for most states, too many, they disenfranchise prisoners, except for those who come from that locale, which is quite rational. Most States disenfranchise the mentally ill. So how are they--who else are they going to disenfranchise.

It might be that Justice Sotomayor conflated "prison gerrymandering" (the practice of including prisoners in the district where they are imprisoned for purposes of determining the total population in a district, rather than deeming prisoners residents of where they last lived before being imprisoned) with felon disenfranchisement--that's the only way to make sense of the "except for those who come from that locale" remark. But the comment regarding "too many" states that disenfranchise "prisoners" (which, as I last checked, was every state except for Vermont and Maine), as opposed to ex-felons, stood out listening to oral argument.