The word " swamps" is a relative term. I' m from Michigan and cedar swamps here can have a lot of different stuff, but generally Michigan swamps indicate thick, close quarters with a great deal of moisture, if not downright flooded.
Deer can and will use swamps for protection....from weather and hunters. They will use them for browse when their favored foods are too risky or pressured. But they will often use them as safe bedding, usually staying toward the edges unless pressured.
Bucks however, in my experience, can take up nearly permanent residence in swamps for the daylight hours, and can be found holding tight to some of the thickest, nastiest scrub tangles that you have ever seen. I love hunting swamps, but have gotten many more shots just outside swamp edges when the deer are moving in or out at first or last light. The cool thing about swamps can be the amount of other wildlife you notice while sneaking and peeking for whitetails.