When that happens, their are times nothing will work; that is Legal..LOL
I have been caught in that situation before and could not get a bite because the Bass where keyed in on dying shad. Other times the shad are stressed and its just hopeless because of the amount of bait in the areas.
I have tried, flukes, top water ( sammy, pop-r's, walk the dog baits) spinner baits, both 3 blade and 2 blade as well as waking them.
Shallow running crank baits, and even floating worms, to no avail.
Have heard of guys having success in that situation with a spoon that will flutter on the fall. But most of the time I have run into those situations is in the back of coves as the water is warming fast and this creates a shad die off (shad can not handle water that warms up fast) this time of the year.
There are just situations you will find while fishing that time to move and try and find a different spot.