Rainville Robo-Call?

We've received robocalls from candidates in the past, so they're not
a major surprise. We expect them from left-wing candidates because
we've signed up to support them in the past. We don't expect them
from right-wing candidates because we never offered them our names or
contact information. But still, we get unsolicited contact from
Tarant's campaign as well as Rainville's from time to time. It's
annoying, but we don't raise a fuss over it because it's expected
during campaigns.

This, however, is a bit different: for the past few weeks, we've been
getting hangup calls from the caller I.D. # "000-000-0000"

No one ever left a message on those numbers, until tonight.
Tonight's message was a robo call explaining how Martha Rainville was
the best candidate for Vermont, etc.

Now, I expect to get calls sometimes from unlisted numbers. The
"000-000-0000" item, however, is different. It means that software
is being used to actively fake the phone number.

To be clear: I'm not sure where this call came from. The robospeaker
didn't identify himself and there was no indication of who sponsored
the call. Clearly, the anonymous caller supporting Rainville is
enough of a coward that he doesn't want to be identified or reached.

I'd like to know if Rainville's campaign has anything to do with
these harassing phone calls and, if not, who is behind them.