The title of the puzzle contains the word STATE. The hint contains the words ADDRESSING, LETTERS, and MAIL. All of the words in the headlines are built from two-letter pieces. They string together United States state abbreviations used for addressing letters and other mail. For example, the abbreviations for Missouri and Mississippi form MOMS.

MOMS DEMAND FLORAL MEMORIAL IN MAINLAND GALA
LASCAR INKS MANDARIN COAL MINE DEAL
ARCADE GAME INCOME GAIN ALARMS MAMA
COOK MADE CALAMARI OR MAHI MAHI MEAL
MARINE ARMS LAND MINE IN DEMO

These are the state abbreviations: AL AK AZ AR CA CO CT DE FL GA HI ID IL IN IA KS KY LA ME MD MA MI MN MS MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI WY