CNN: “In many ways, Janet Mills is the ideal Democratic recruit to take on Republican Sen. Susan Collins, a fifth-term moderate with a track record of beating well-funded challengers. Mills is a two-term governor with a history of outperforming her party and a record of pushing back against President Donald Trump.”“But there’s one issue her detractors raise: She’s 77. If she beats the 72-year-old Collins next year, Mills would become the oldest freshman senator in history.”“Mills’ formal entry into Maine’s Senate race Tuesday sets up one of several primaries that could be fought explicitly or implicitly on the issue of age. A series of midterm races will test whether Democratic voters are looking for proven commodities or a new generation of voices as they grasp for a foothold on Capitol Hill for the last two years of Trump’s presidency.”