Someone who thought Donald Trump was gonna be re-elected in the 2020 election. MAGA is Trump's slogan that stands for "Make America Great Again!" Getting cucked feels like something getting stolen and you become jealous. If you combine the two, you get the word, "MAGACUCK."
Guy 1: TRUMP 2020! 4 MORE YEARS OF LIBERAL TEARS!
*Trump loses*
Guy 1: WTF! THE ELECTION WAS RIGGED!