Dan Koh should take a bow. He may not have been instrumental in getting freshman U.S. Rep, Lori Trahan to come out for the impeachment of President Donald Trump, but it sure looks that way. And, who knows? Koh may be running against Trahan for Congress again. In a large field of candidates, Trahan beat Koh by only 147 votes following a recount in the 2018 Democrat primary. So, it could be that Trahan, who now holds the Lowell-based 3rd Congressional District seat, could be hearing footsteps. The seat previously held by Rep. Niki Tsongas of Lowell, who did not...