An expert witness who testified in the RNC case estimated that “approximately one-third of a [percent] of non-Hispanic White voters [in Arizona] are Federal-Only Voters, while a little more than two-thirds of a percent of minority voters are Federal-Only Voters.” So the universe of voters who registered using the federal form isn’t that large, but it is disproportionately non-white, which likely explains the GOP’s interest in this case — among other things, Republicans wanted to prevent these federal-only voters from casting a vote for president.

In 2020, President Joe Biden lost white Arizona voters, but very narrowly won the state due to his strong performance among Latinos. Biden’s margin of victory was only about three-tenths of a percent, so even a small shift in who was allowed to vote in Arizona might have changed the result.

I can’t parse this. They can’t possibly be saying 0.33% of non-Hispanic white voters are federal only.