TexasCHLforum.com

You got it. Here is the law on resisting arrest:

Sec. 38.03. RESISTING ARREST, SEARCH, OR TRANSPORTATION. (a) A person commits an offense if he intentionally prevents or obstructs a person he knows is a peace officer or a person acting in a peace officer's presence and at his direction from effecting an arrest, search, or transportation of the actor or another by using force against the peace officer or another.

(b) It is no defense to prosecution under this section that the arrest or search was unlawful.

...wonder if it could have referred to PC9:31 (c)...

The problem with posse comitatus, like any law meant to stop government abuses or oppression is that the same government which committed the offense has to prosecute itself for it. In most cases, that means coverup and making some the fall guy.

The us has used troops against civilians. During the depression, Hoover ordered an attact on WWI veterans in which cavalry and tanks commanded by none other than Douglas MacArthur (a real d-bag from much of what I've read). Look up the Bonus Army.