I think he explained what he meant by the previous paragraph.

There's no proven fraud in voter id laws, gerrymandering or "regular closing of the polls{sic]":

- Voter id laws are necessary. Nearly every democratic nation in the world uses voter id laws:

https://duckduckgo.com/?q=how+many+nations+use+voter+id+laws...

-gerrymandering is commonplace. Both Republicans and Democrats do it:

https://www.thoughtco.com/what-is-gerrymandering-4057603

There is no clear possible political solution to gerrymandering. When Democrats get control of state legislatures they gerrymander to their benefit; when Republicans get control they do the same.

or

- regular closing of the polls. Polls must close early enough so that the vote can be counted and go in. The hours are rarely if ever extraordinary.