It was his first time at the ranch, but he was with a group of 35 people invited to the ranch by Poindexter. He in turn had been invited by some personal friends in the group, along with his son (who at the last moment couldn’t come along). I don’t know what the occasion was, but he was obviously among his own friends, even if he didn’t know Poindexter.
And he also knew how to separate the personal from the political, a virtually lost art nowadays...
I know someone who has been on a few hunting and fishing trips with Scalia. He went on them fairly frequently and always went to the best places, I don't think he was at all concerned with the politics of the owners.
As far as Poindexter goes, if he didn't know how to get along well with conservatives and other Republicans, he never would have made it as a hunting ranch owner.