These industry leaders each have a mathematically clear path to join the exclusive $3 trillion club.Much of what drives the U.S. economy has changed over the past couple of decades. For example, energy stalwart ExxonMobil and industrial bellwether General Electric were the two largest publicly traded companies by market cap in 2005, valued at$375 billion and $362 billion, respectively. Fast forward 20 years, and technology companies -- particularly those well-versed in artificial intelligence (AI) -- lead ...