Gov. Janet Mills is not dropping out of the U.S. Senate race despite trailing in the polls and having no advertisements booked after Wednesday, her campaign spokesperson said. Speculation online about the potential for Mills to drop out, fueled primarily by supporters of her competitor, Graham Platner, mounted this week as ad spending data compiled by AdImpact showed Mills having no ads booked in the coming days. “As the only Democrat elected statewide in Maine in the past 20 years, Janet Mills knows how to win tough battles and deliver results — and that’s why she’s the best candidate to...