A new poll indicates longtime Republican Sen. Susan Collins is ahead of her Democratic challenger in a crucial Senate showdown in blue-leaning Maine. Collins, who is running for a sixth six-year term in the Senate, stands at 49% support among likely voters, with former Maine Senate President Troy Jackson, the Democratic nominee, at 46%, with 5% undecided in the New York Times/Siena poll. Collins' three-point edge is within the survey's margin of error. Democrats are heavily targeting Collins as they work to flip the seat, which is key to their efforts to win back the Senate majority from the Republicans...