Plenty of actresses can hold your attention while half-dressed in a bra and slip, but can you think of one who can get you to forget what she's wearing and instead try to figure out what's going on inside her head? Think of Debra Whitfield, who portrayed a self-possessed political lobbyist in Michael T. Folie's The Adjustment at the Florida Stage. Whitfield spent much of her stage time in her underwear, but there was nothing flimsy about her performance. In this Florida premiere, smartly directed by Gail Garrisan, the actress maneuvered her character around the stage with the confidence of someone who could lead a small country into war and never lose concentration. Whitfield may have displayed a lot of flesh, but her performance was all heart and brain.