The problem comparing your quote with american states is the phrase "long been run". Boot is talking on time scales longer than the US has existed.

Most american states have flipflopped between Republican and Democratic multiple times in the last 160 years since the disappearance of the Whigs. (And the parties themselves have swapped positions several times during that space.)

Even a deep blue state like Illinois was under trifecta Republican control as recently as 1996. Deep red Missouri was under trifecta Democratic control from 1993 to 2000 (and has had Democratic governors for 20 of the last 30 years) and used to be a bellweather state.