These two sentences, for example:
> Fairly considered, the Texas legislature is more functional than the United States Congress, and more genteel than the House of Commons. But a recurrent crop of crackpots and ideologues has fed the state’s reputation for aggressive know-nothingism and proudly retrograde politics.
As far as I can tell, even though they are in the same paragraph and nominally about the same topic, and joined together with that "But", they have nothing to do with each other. To me it looks incoherent.