As America waits for who wins the presidential race so are large tech behemoths who have a large stake in who wins. Under the incumbent president, there is no doubt that they have enjoyed some very handsome tax incentives. This has increased their profitability handsomely. However, they have run up against some policies that they are also not happy with. There have been antitrust lawsuits aimed at them. Immigration is another where they rely on bringing in foreign skilled workers to fill their needs. Of course, they have run up against new legislation which threatens how they conduct their companies. The friction with china threatens their access to what they see as a major market.
It is no secret that the incumbent president wants them to close their facilities there and bring them back home. Americas standing in the world which helps immeasurably in people coming over into the US and set up businesses they have spun off from their development efforts is also a big prize they fear for.