It’s not a “woe is me” defeatist attitude. It’s more of a”know your enemy”. We know democrats have always cheated, but this last election they amped it up to a much higher degree. Because they were desperate. With no repercussions for their actions, and with their obsession to keep Trump from winning in 2020, it’s not an exaggeration to think they will do whatever they need to steal that election. I don’t think there would be a “comfortable” margin to prevent that.
Resign for what reason? Because elections are hard? Because our opponents cheat? Because they'll cheat even more in the 2020 election?
All of these are obstacles in the way of the ultimate goal, re-elect Trump in 2020.
Leaders like Trump don't let a few obstacles get in the way of their target.