Massachusetts has open primaries, so independents can pull a ballot for either party. Independents will without a doubt break for Chris Doughty (who is positioning himself as a moderate republican). Hopefully the independent vote will outweigh the crazy so that Diehl does not make it to the general.
Honestly, this race is Maura Healey's to lose. Diehl is a many-time loser (lost by 24 in 2018 to Elizabeth Warren) and his only claims to fame are getting an incredibly unpopular gas tax hike scheme eliminated via ballot initiative and then being the biggest Trumper in a state that went for Biden by 33% in 2020.
I don't know too much about Doughty, however I'm someone that follows MA politics and... shouldn't I know a lot more about him if he has a real chance?