Joe Biden is set to join striking car workers on a picket line in Michigan on Tuesday ahead of a separate visit to the state by Donald Trump later this week, as the political battle for blue collar support heats up in industrial America ahead of the 2024 presidential election.  

The move by Biden is seen as historic because his predecessors have seldom sided with workers in labour disputes, and he has cast himself and gained credit from the left of the Democratic party for being the most union-friendly US president in decades. 

But Biden’s decision also reflects the difficult reality for the White House that he has not locked up the support of rustbelt voters ahead of the election, despite policies designed to boost industrial America through sweeping manufacturing subsidies.