Here is how RAW STORY summed up the plot:
In the episode, characters Eric Northman and Pam De Beaufort dress up in stereotypical Texan Republican trappings to infiltrate a Cruz fundraising event in Dallas. “Oh my God. I’m a Republic*nt,” Pam remarks after seeing herself in the mirror.
Ted Cruz responded to the show on his Facebook page, saying, "Of all the places I never thought to be mentioned, HBO's True Blood vampire show would have to be near the top of the list. Sunday night, they aired a misogynist and profanity-ridden episode where Texas Republicans are murdered attending a "Ted Cruz fundraiser." Well, I'm sorry to have lost the vampire vote, but am astonished (and amused) that HBO is suggesting that hard-core leftists are blood-sucking fiends...."
Here is the scene from the show: