ActBlue Link:
My normal policy prior to a state primary is to only list incumbent Democrats, and to only list non-incumbent candidates prior to the primary if a) I'm personally endorsing them (i.e,. Elissa Slotkin for MI-Senate) or b) if they're the only Democrat running anyway.
Exceptions to this are when they have no serious primary challenger, which admittedly can be subjective, but I trust the Daily Kos Elections team on this issue:
Former state education superintendent Jennifer McCormick, a former Republican who has no serious opposition for the Democratic nomination, took in $150,000 and ended 2023 with $201,000 available.