I expect that GP meant broadly opposed [amongst the population]. You could argue that even with this assumption, it would qualify, as 7 in 10 Americans do thin

I expect that GP meant broadly opposed [amongst the population]. You could argue that even with this assumption, it would qualify, as 7 in 10 Americans do think the insurrection was wrong. But I can see the merit in arguing that 3 in 10 supporting it is uncomfortably high.