Micah Jones, a former self-described JFK Democrat-turned-Republican, hopes to capitalize on a “once-in-a-lifetime” opportunity as he looks to flip Massachusetts’ 6th Congressional District.“The last time this seat was open was 47 years ago,” Jones said.“I think that Massachusetts suffers when we have a one-party congressional delegation that, in my opinion, is less inclined to work across the aisle than representatives of other states.“Jones’s campaign is a bet that the district’s independent voters — and maybe some Democrats — will see the benefit Massachusetts could reap from having even just one Republican representative. Coupled with the precedent of the occasional Republican success is the B …