Geez, Mr. Harvey is a pretty slow learner.
While I don't support the group or its goals, they actually do have a valid point about the annexation of Texas. It's articulated incorrectly in this article, but the US Senate never ratified the treaty of annexation. Because of concerns over admitting another slave state to the union, getting a 2/3rds vote in Senate wasn't possible, although it was attempted.
Instead, Texas was admitted by a majority vote. That's not constitutional, but it's a little late to do anything about it now.
What's on the sheriff's wall? Bobcat?