WASHINGTON – More than 200 companies and politicians in the US, including some of the country’s largest utilities, have signed a voluntary pledge to prevent AI data centres from driving up electricity costs for millions of Americans, President Donald Trump said on July 23.The pledge is largely symbolic, and experts have said it could be difficult to enforce because power prices are often determined by state regulators. But it underscored the extent to which rising energy bills have become a top concern for voters – and a potential liability for Republicans – ahead of the midterm elections.Trump first announced the...