You can---or hire someone to reset the entire door assembly---cutting the fasteners that fasten the door frame to the house framing and realigning the frame.

Sometimes it's just a matter of tweaking the hinges, either tightening them up, or just shifting them a tiny bit, but you generally need to know exactly what you're doing (experience definitely helps) or you can end up with just another problem.

Who do you hire to realign a door?

You'll have to ask around (maybe start with high-end custom door/window places) but you should be able to find someone that does doors and only doors. These people don't come cheap.

From the looks of things, resetting your doorframe isn't trivial because of the sidelights.

Easy things first: doublecheck that the hinges are screwed tight. If you feel adventurous, try shimming behind the bottom left and the top right hinges. (Just a couple of layers of business card.)

If you have access underneath, take a look at the structure and make sure there's nothing bad going on that would cause the doorframe to rack.

I wouldn't go after the doors with a power planer until I had absolutely assured myself that the root cause of the problem wasn't elsewhere.

The door or the house looks to have dropped on the left side of the picture.

Check the perimeter of the door opening with a level first. If that is OK tighten the screws and shim the hinges until the doors are properly aligned.

If the door frame is out of square you should hire a good finish carpenter. Ask around to see who others have used.

You can buy shims that are cut the same as most radiused hinges, or you can simply cut your own using thin cardboard. To raise the profile would involve shimming the lower and middle hinges with more shims at the bottom, in another words, maybe two shims on the bottom hinge, one in the middle, or what ever it takes to make the reveal even at the top and the alignment good with the other door.

The house had some foundation repair in the early 1990s -- we live on the side of a hill in So. Cal., and there were a couple of really big earthquakes at that time. No other door in the house is out of alignment. I believe the POs fixed the foundation and simply did not fix the front door -- which is a good thing because they would have put in the HD special of the week. :/

It sounds as though I will need to replace the door frame, though.

The frame doesn't need to be replaced. It could be simply re-aligned in the opening.
This would require removing the trim on the inside and outside and adjusting the current door/window frame in the rough opening. The left side needs to be raised slightly. The right side could probably be left alone.

Awesome! Thanks. I'll have to find a carpenter who can help.