If we lose power in OK, I'm headed to Port A. Any fishing I do will be confined to the jetty, piers, or surf. What's my best chance of catching something, and I don't much care what?

Well, first off.. you WON'T be in OK... So come on down! Jetties how a lot of fish all year.. there are some good sheeps heads holding on the rocks and can be caught with hermit crabs. Still a few Bull reds in the surf as well... half crab or cut mullet should be a good option. Will be some pompano showing up as well here or there. There's also some good wadefishing back in the bays where you can find walk in access. Might need a pair of hip boots to keep the water off and stay dry. Chest waders would be better, but both are doable in port a area. You can use bass lures and tackle to catch redfish and trout. Any small bone topwater walker or a gold spoon or spinner bait can get you bit.

have fun

Galveston is closer.

Actually it's an optical illusion.
Port O' Connor is almost the same driving time as Galveston, add in Houston traffic and you're usually ahead.
Neither one of them would be as good as Rockport/Port A if you're boatless.

Mr. goff is dead on,if you want to fish port o andathat area is is amuch better ride from D.F. W..