Regrettably, SMS campaigning appears to be the new norm, as both major political parties are utilizing it. The calculation seems to be that the advantages outweigh the drawbacks. Therefore, I don't believe a bad actor would utilize it to potentially help their opponent.
From personal experience, while the constant messaging can be irritating, I've learned to reply STOP and move on with my life. it won't deter me from voting. I mean, this tactic is part of broader campaign strategies rather than a reflection of any candidate's merits.
We had a local election back in 2004, where Candidate A unleashed a spam tsunami at text and voice numbers. Enough that it angered enough people to turn the election to Candidate B. (best as we could tell after the fact)
Candidate B, it eventually came out, was the one who was running a sock puppet "Vote for A!" campaign.
From personal experience, while the constant messaging can be irritating, I've learned to reply STOP and move on with my life. it won't deter me from voting. I mean, this tactic is part of broader campaign strategies rather than a reflection of any candidate's merits.