I've seen that phrase on bumper stickers many times. It's fully unironic, and earnest.
It's right up there with people who fly a blue line flag and a Gadsden flag together. Or the stickers that show a cross, a gun, and a heart. I saw one recently that was the word LOVE spelled out with various firearms.
They don't have coherent ideologies. It's just reactionary bullshit that's wildly incompatible, but they're too blinded by their bigotry to see it.
Related, I'd always heard that the /r/the_donald started as an ironic shitpost sub that was taken over by people who agreed with it unironically and then became 100% serious.
Poe's Law, and all that.