I recently picked this up at Lowes. I repotted it because the roots were growing out the bottom of the container. I used potting soil mixed with a bit of cactus mix for extra drainage, watered it, and this is what happened. What, if anything, can I do to revive it? Thanks for any ideas

Did you disturb the roots when you repotted it? Just keep it warm and very bright.

It looks like Croton (Codiaeum variegatum 'Aureo Maculatum') and it likely didn't need to be repotted. It's quite normal at times for roots to escape the drainage holes in search of moisture. The new pot may be a bit large for the size of the plant and the fine feeder roots may have been damaged during the repotting process but keep it in a warm location with bright light and barely damp soil throughout and it should eventually perk up and recover.

It should be fine.

Give it time and don't over-water, if there's too much soil without roots yet it will stay soggy.

What'd it look like when you knocked it out, if it was root-bound up-potting was probably good.

If there was still a bunch of soil and just the stragglers coming out the bottom I'd give it a while longer.

If it got too cold on the way home, that could cause the leaves to hit the ground.

Thank you all for your advice. Poor little plant, so far no leaves have actually fallen off the stem so I'm hopeful. They're still drooping, though. Usually, I try not to repot my plants because of the tender root system, but I thought that it was necessary once the roots grow out of the bottom of the container. If this isn't necessary, then I won't worry about repotting. Every plant I have seems to be an experiment. LOL

Happy to suggest. And totally agree, all new plants are an experiment. Even if it's a same plant you've had and done well with before, you don't know what experience(s) your new plant had right before you got it. I don't repot plants, generally, between first and last frost because they're inside and the weather isn't amenable to the fastest possible recovery from disturbance. If it's not drying too quickly for your schedule, I would recommend waiting until the days are warmer and longer.