It looks like nutsedge to me. Does it come right up when you pull it?

That does look a lot like Yellow Nutsedge. Sedges evolved in wet areas, swamps, bogs, fens, and grow best in soils that are kept wet. How often do you water your lawn?
Clay soils, lacking sufficient amounts of organic matter, will often not allow water to penetrate but will create the surface conditions, wet, that Yellow Nutsdedge likes to grow in.
The only poisons that will kill Yellow Nutsedge will also kill any other grass the spray touches.

Wrong on all counts, Kimmsr. Nutsedge is a common weed of many types of soils and moisture conditions. It will thrive happily in non-irrigated sandy soils, well-drained loam, and clay.

And the herbicide Image is labeled for the control of nutsedge in all of the warm season grasses, such as Centipede, St. Augustine, and Bermuda. Image has been around for many years and is the herbicide mostly likely to be commonly available. Another chemical is Sledgehammer, which can also be sprayed over warm-season grasses. It might be more difficult to find in the run-of-the-mill garden centers. Both can also be used in ornamental beds.

Here is a link that might be useful: Clemson information for you, Sarah

Once established Nutsedge can grow in dry soils but it evolved in wet swampy soils and much prefers growing there. Most often I see it growing where the lawn is watered daily.

Here is a link that might be useful: Nutsedge