The reason those who swore allegiance to the Confederacy were disqualified was precisely that: they took an oath to support a different government.
The equivalent to the same today is in this Code section: .
18 U.S. Code § 2383. If someone is convicted of insurrection under the statute, they are barred from federal office.
No one has been charged or convicted of insurrection here. No one took an oath to support a different government.
A riot occurred for a few hours on a single afternoon. That is not at all the same.
Otherwise all those who rioted, looted, burned down buildings, set fire to cars, and killed people during the 2020 8 month long riots are insurrectionists and should be hunted down and charged with the same vehemence and millions of dollars expended on this group of 1000 or so, who were mostly charged with "being in an unauthorized area" and "parading" - with a handful of exceptions, charged with property crimes or the 4 oath keepers/proud boys charged with conspiracy.