Normally, this would be a flapper or drain pump issue. However, the reason for the excess water was a bad fill valve - the fill valve was very slowly dripping out water thus filling up the bottom of the dishwasher. The rubber seal in the fill valve had deteriorated with time. I suspect that many Frigidaire dishwasher not draining issues are due to water leaks from the fill valve and not from the drain pump or flapper valve.
To detect this problem you can place a paper towel on the fill water outlet port. You also can see if the amount of water in the bottom of the dishwasher increases over time after the wash cycle is complete.