I have been struggling for years on trying to grow geraniums on my front step. My step faces due west, so lots of afternoon sun, not so much in morning. The buds reach full growth but die out when they open. Am I over watering them? Over fertilizing? Not enough sun, too much sun? I am at a total loss.

Too hot an afternoon exposure might be a factor.
However, have you inspected the buds/flowers? Geraniums are often attacked by caterpillars that feed on the developing buds and the flowers.
You will see little holes in the buds which collapse and die soon after being attacked. These caterpillars also go after the opening flowers. These could be the cause of your problem.
Treatments could vary. I always found that picking them off the plants was very easy. I never grew more then a dozen geraniums or so, so this was not too hard. You could also try a dust or a floral spray. The caterpillars give away their presence by leaving their bug poop behind on the leaves of the geraniums. It looks like little peppercorns.

Thank you for your reply! I have really inspected them and have not found any evidence of bugs/caterpillars

Your's are Martha Washington Geranium which are also called Regal Geranium. I think they prefer morning sun and shade in the afternoon.....depending on your climate. The area where you are growing them might just be to hot. You would probably have better luck with the Zonal Geraniums.

They would prefer morning sun and dappled afternoon sun. I grow pelargoniums not geraniums but they do share similar attribute. Flowers need the sun but too much duration of it will blast them quick.

Then depending on ambient tempertures too, over here they like our 60F to 75F range. Beyond that is frying time. Your area might have better temps than mine, but the amount of full sun they get will affect it. Refrain from fertilizers too if is visibly in distress.