Gov. Janet Mills’ U.S. Senate campaign has no advertising booked in her Democratic U.S. Senate primary after Wednesday in a notable dropoff following her blitz against frontrunner Graham Planter. Mills’ reservations totaled more than $1 million between March 1 and Wednesday, and last month she unleashed a blitz of ads seeking to reignite criticism of Democratic primary frontrunner Graham Platner. Those ads haven’t curbed the Sullivan oyster farmer and military veteran’s lead in polls. The governor’s campaign has $445 in ads — essentially nothing — booked for Wednesday and nothing after that, standing in stark contrast to $229,000 for Platner...