> How am I supposed to know "offensively excessive" wasn't the intended meaning here?
I'm guessing if it were the intended meaning, "but" would be incorrect in "Republicans will not like many of these proposals, but they have been fulsome in their praise of Mr. Trump since his election"
I mean, if it's "offensively excessive" from the writer's point of view, then I feel like it'd make sense even with the "but"; that's indeed how I took the sentence to mean.
