The idea is that the large tech companies are overwhelmingly staffed and lead by people who qualify as the political left by American standards. As Breitbart sa

The idea is that the large tech companies are overwhelmingly staffed and lead by people who qualify as the political left by American standards. As Breitbart said, "Politics is downstream from culture." - so if you have the most important communications platforms the world has ever seen all privately owned and operated by "the left", that sounds like a bad thing if you're on "the right", because they can shape discourse however they want - either overtly by banning people for bad politics or covertly by shadowbanning and otherwise muting popular voices with undesirable opinions. Imagine if Google/Facebook/Twitter were owned by the Koch brothers and staffed by members of the Federalist Society and Heritage Foundation - people on the left would be doing the same thing Tucker Carlson is doing.