This past weekend, close to 200 left-wing parties gathered for a national trade union conference in Stockholm.
In the party leader's speech, it became clear again that the Left Party's strategy for growing is to try to win disappointed LO voters who are tired of the concessions to the Center Party.
"During this term, the unions have been ignored by the Social Democratic government, which has forced Sweden's workers to bow to the small Center Party and the employers' organization, the Confederation of Swedish Enterprise," said Nooshi Dadgostar (V).
Hard words that probably made it boil a bit in the LO castle.
But it is a logical attack if the ambition is to become a redder variant of the party that the Left Party has always been in the shadow of.
"Made the eco-socialists in the party look red"
That ambition did not come with Nooshi Dadgostar (V).
Becoming a more elective, pragmatic and responsible party beyond radical slogans and unrealistic economic policies was what Jonas Sjöstedt's (V)'s entire project was about.
Nooshi Dadgostar's (V) contribution to the establishment is a new technology-optimistic and growth-oriented industrial policy that has made the eco-socialists in the party see red but where the party leadership sees potential to grow in mills.
Among dissatisfied workers' voters and LO members who were attracted to SD.
Another ingredient is a clear dose of left-wing populism.
A recurring theme in Nooshi Dadgostar's speech is the secular "professional politicians" who "lost contact with the people there are set to represent".
And unlike her representative, she seems very comfortable with that rhetoric.
But despite successes in public opinion, the fight for LO voters is slow.
Admittedly, the Left Party has increased by almost four percentage points in that group since 2018 according to SVT / Novus, but the Social Democrats are more than twice as large and the Sweden Democrats just over 12 percentage points larger.
Perhaps even more frustrating for the left-wing parties is that the Moderates at the same time more than doubled their support among LO members.
What is it then that makes the LO voters seem so difficult to flirt with the Left Party?
One explanation is migration policy.
The Riksdag's most refugee-friendly party is not an alternative for those workers' voters who see a stricter immigration policy as the most important issue.
Another obstacle is identity politics
Another obstacle is identity politics.
Anti-racism, LGBTQ issues and feminism are hardly what LO men in the mill put at the top of the agenda.
Even history can put a dent in the wheel.
Because despite the fact that the Left Party has spent years washing away its communist past, there are probably one or two older LO voters who have not forgotten the battles.
Or as Stefan Löfven (S) put it in a DN interview this spring "Communists and Social Democrats have always been in each other's shoes".
There are several obstacles along the way, but the generation of Left Party members who now control the party seems convinced that they can be bridged without having to reconsider politics.
Because if they tried such a maneuver, they would not only get an internal revolt around their necks, they would also risk the support of young progressive voters that has been crucial for the growth of recent years.