President Donald Trump on Thursday had governors and electricity companies join a voluntary pledge to shield U.S. consumers from higher utility bills from data centers — a sign of how the artificial intelligence build-out has become a lightning rod of controversy before the midterm elections. The president first announced the pledge with leading AI and tech companies in March, but that initial commitment has done little to comfort voters who are already grappling with affordability issues as they worry about competing for electricity, water and land with tech companies controlled by billionaires. It’s unclear, with electricity demand already growing, whether consumers would see genuine savings….