Democratic Maine Gov. Janet Mills announced Tuesday she is running for Senate, a massive recruiting success for the party as it aims to finally oust GOP Sen. Susan Collins in a consistently blue state. Mills, 77, has a demonstrated track record of electoral success in Maine, winning the last two gubernatorial elections by 7 percentage points and 13 percentage points. Collins, while consistently unpopular in public polling, is a strong fundraiser who has managed to secure support from Democratic