Nah, if you want to point at the thing that made all this happen..then its not MAGA.
it was Gamergate.
Gamergate was the prototype and test run for the foreign provocateurs, right wing extremists and other hate mongers to see how successful such a large scale attempt at manipulation of narratives and communities could be.. and it proved quite successful, and the same tactics and methods were scaled up even further to lay the groundwork for Trumpism and what we have today.
Gamergate was the Trinity test that lead to Littleboy (general uptick in rightwing extremism/fascism/alt-rightism and approval of such) and FatMan (Russian "Useful Idiots" who came to power, or threatened to, with Russian backing, not just in America, but elsewhere)