To do that, select the frame of a SmartArt object. You can assign a hyperlink to any SmartArt object or group of SmartArt objects. The text itself will be underlined and colored. Select the the text within a shape, and the rest of the shape area will not be clickable. If you have placed text within a shape, it will not be underlined or colored. You can add a hyperlink to any shape or group of shapes.
Select the text only, and the rest of the text box will not be clickable. The text will not be underlined or colored. Select the frame of a text box, and the whole area, including the white space around the text, will be clickable.