Data centers have become the face of AI backlash, with celebrities, politicians and protesters pushing to slow their growth. Why it matters: America's sharply rising public opposition to data centers — which fuel our everyday use of the internet — could pose an existential threat to AI's growth. State of play: There are at least 4,000 data centers nationwide, with some 3,000 under construction or planned. - The centers are often big, windowless warehouses with few people in sight, and many are developed in secrecy . Driving the news: Data centers have become a focus of anti-AI sentiment, with 70% of Americans opposing their construction. - Former NFL star Jason Kelce announced a partnership between his Garage beer company and…