In late March 2020 the national lockdown stopped work across Punjab's industry and construction. Several lakh migrant workers, from Bihar, Uttar Pradesh, Jharkhand and Odisha, were left with no income, no savings and no transport.
Some walked. Some waited weeks in the industrial mohallas of Ludhiana on food distributed by gurdwaras and by residents. Shramik special trains ran from May and moved very large numbers east.
Punjab discovered publicly what it had known privately: that its industry and its agriculture run on people from outside the state who have no political representation in it and no claim on it.
Most came back within a year, because the work is here and it is not there.
The episode produced a short period of public attention to migrant conditions in Punjab and no lasting change to housing, registration or entitlement.
More than eight lakh migrant workers registered to leave Punjab in 2020, and the movement lasted about eight weeks.
The trains east fill before the eastern festivals and empty the industrial belt for a fortnight. Ludhiana's units run short and the mandis feel it at the same time.
The 2020 lockdown made the movement visible. Special trains carried hundreds of thousands out of Punjab and the industry took months to get its workforce back.
The relationship is three decades old and largely stable. What it has not produced is any political representation for the workers inside Punjab, who vote where they are registered, which is elsewhere.