It looks like what I have is most likely tibialis posterior tendonitis. It make sense because it's in my right ankle, which from what I've read is the likely spot if you're running on the left side of the road all the time. It also happens to be the ankle I broke last winter playing basketball, which could also be a factor.
It's too bad because my workouts have been going so well. I ran 11 miles yesterday including 4 X 1 mile around 6:04--almost 30 seconds per mile more than the workout called for. I didn't have too much pain in the ankle yesterday but today it was pretty bad.
So, it looks like no running the rest of the today and most likely elliptical machine tomorrow. Then we'll see what happens on Saturday.