A Designated Market Area (DMA) is a media market, a group of counties that account for the major viewing audience for television stations located in a metropolitan area.
States usually encompass one or more DMAs, though there are anomalies (VT, DE, NJ). House districts, however, do not coincide with DMAs. See, for instance, California's DMAs (left) v. US House districts (right)
Marco Rubio hits some key themes:
Compare Florida Senator and Governor exit polls.
In Kentucky, the big issue was Aqua Buddha: