On Saturday, American opposition to data centres stopped being a scatter of zoning-board arguments and started behaving like a movement.

More than 140 rallies across 42 states unfolded under a single banner, in what organisers billed as the first national day of action against the industry pouring the concrete for artificial intelligence.

The rallies were coordinated by HumansFirst, a group co-founded by the former Tea Party leader Amy Kremer, and they arrived after months in which local campaigns had already stalled dozens of projects.

Data Center Watch, which tracks the fights, counts tens of billions of dollars in construction blocked or delayed by community pressure.

Texas hosted the most events, with 18, followed by Georgia with 11 and California with eight. The map is the point: these are red states and blue states, and the coalition threading through them, part conservative tax revolt and part environmental campaign, refuses to sort along the usual lines.