Updated to add Ted Hess-Mahan’s endorsement of Nicole Castillo.
There are three City Council races where a successful challenger will guarantee an incumbent is unseated: Ward 1 At-Large, Ward 2 At-Large, Ward 5 At-Large, Ward 6 Ward*. In
two three of those races, sitting councilors have taken the unusual step of endorsing challengers.
In the Ward 5 race, councilors Alison Leary, Deb Crossley, Jake Auchincloss, and Ted Hess-Mahan have endorsed Andreae Downs, whose victory would displace one of the incumbents, either Deb or Brian Yates. Reading between the lines, fair to say that the endorsements are intended to help Andreae defeat Brian (particularly Deb’s!).
In Ward 6, Deb and Alison are joined by Susan Albright to endorse Brenda Noel, who is challenging 4-term incumbent Dick Blazar. In Ward 1, Ted endorsed Nicole Castillo, who is challenging incumbents Jay Ciccone and Alison Leary. Ted also endorsed Alison, so we can deduce that he prefers Nicole over Jay.
As far as I can tell, there are no councilor endorsements for challengers in the Ward 2 race.
If I remember correctly, sitting councilors never use to endorse challengers against incumbents. In the last ten years, maybe there have been a handful. These endorsements seem to be serious statements of support.
* In the at-large races, there are two incumbents, meaning a challenger win (first or second in the polls) would unseat an incumbent. In the ward race, incumbent and challenger are vying for a single seat. In Ward 3, both challengers (Andrea Kelley and Julie Malikie) could outpoll James Cote and unseat him. But, at least one of the challengers will win and Jim could still retain his seat. Andrea has a slew of endorsements from sitting councilors.