I would opt for a 4 wheel alignment first. your rear wheels may not be tracking in line with the front, there by causing you to move down the road slighty sideways, making you adjust the alignment with the steering wheel.
I slammed mine out of whack and took it in to have the alignment checked just in case. It was fine and just took the drag link adjustment to correct it. Looks like maybe my trackbar bumped and moved the drag link adjustment bolts when I flexed or came down hard.
looking for the next off-road trip