They are sell outs & this is a power grab. They determine that the way to cool down the tone in DC is by undercutting everyone who is even slightly to the right of the MSM. They think things are still the same as the time of Nixon, when the left dominated both parties. They imagine themselves as leaders & are trying to drag their party back to the left. They fail to understand that if the country leaned as far left as they are, the Dems would still be in power.
I DO think these seven have screwed themselves. they will get a pat on the head from the MSM for a week, and never get any more Dem votes. While losing their base, in their state and nationally.
Even in New England, I would assume the average "moderate" (whatever that means) would not know either major party candidate in the next senate election, or be a Dem activist trying to flip the seat. the Republican activists WILL know, and remember, these senators next time. And not to help them, believe me.