It’s one poll, and (sometimes performative) panicked politics leads would-be critics to uncritically back the people in charge. For these reasons, too many leftists position themselves somewhere between cheerleader for and conscience of centrist governments.
For me, the true danger of Alba is that it could amount to nothing. And, in establishing itself, it will have emptied the SNP of many of its most eloquent internal opponents, including Kenny MacAskill and, in all likelihood, many others to come.
Leftists may view Alba as a break from Sturgeon’s dreary post-neoliberalism; nationalists as a break from Sturgeon’s constitutional coquetry; unionists as (an ironic) break on SNP government. Will this add up to a serious vote? It’s late in the day, but theoretically, yes it could.