In a deep fryer (or a deep pot), heat several inches of oil to 375F.
If needed, slice hot dogs in half (width-wise). You'll want to do this if your deep-fryer has a relatively narrow opening (and is relatively shallow), simply to ensure that you'll be able to fit the corn dogs. Remember, you'll be frying the length of a hot dog plus a couple of inches of wooden skewer, so plan accordingly!
If needed, cut down your skewers to a comfortable length. You'll want each one to be a few inches longer than the length of a hot dog.
Gripping a hot dog in one hand, carefully but firmly thread the skewer through the hot dog with your other hand, stopping about an inch from the end. Repeat until all hot dogs are skewered.
Generously dust hot dogs with ¼ c flour until they're entirely coated. This will help the breading stick.
In a medium bowl, whisk together cornmeal, ¾ c flour, sugar, baking powder, and salt.
Whisk in milk; the texture will be similar to pancake batter.
Pour batter into drinking glass.
Gripping a skewer, dunk a hot dog into the batter, spinning it as you pull it back out of the glass. The entire dog (ends included) should have a thick, even coat. If necessary, quickly touch it up with a spoon.
Quickly drop battered hot dog, stick and all, into hot oil.
Repeat as necessary and fry in batches of 3 (depending on the size of your frying apparatus) for about 3 minutes, rotating once half-way through, or until nicely browned.
Serve hot, with ketchup and mustard for dipping!