If you listen to him speak, he's pretty clear that he doesn't identify with either party, politically. There are things he agrees and disagrees on, with both parties. However, one of his biggest causes is public lands, and access to them. And lets be realistic, the Republican party, in general, isn't as protective of them as the Democratic party is. If the Republican party had their way, man of these lands would not be open to the public. They'd either be sold off, of they'd be given over to the states to do with as the states saw fit. Many state constitutions don't allow for operating at a deficit and if they're are faced with such, they're required to liquidate assets to make up for that deficit. Goodbye public lands if that happens.

Rinella is openly pro-2a, for obvious reasons, but he's also a hardcore advocate for public lands. My guess (and that's all it is) is that when push comes to shove and it comes time to vote, he's probably going to vote for the public land guy because (again this is a guess) he likely views public lands as more endangered than gun rights at this point in time.

I don't necessarily agree with that viewpoint (assuming it's even an accurate assessment of his beliefs), but I can at least understand why he might think that way.