That seems to be the same attitude that was proven false when other Presidential candidates lost an election after quitting their previous job. And darnit if they didn’t win later!
So go peddle your “I thought of this so is very very correct and anyone who thinks otherwise is just dumb”.
I can't think of any candidate that quit their day job three years before an election in which they intend to run in, and then win that election, or any other for that matter.
Dole did resign his Senate seat just before the first primary, I believe (could be wrong), but that was his fourth or fifth term and he was a very, very old man. And, he lost.
Bush, Clinton, Bush, Reagan, Carter, Nixon, Johnson, Kennedy - they all were either gainfully employed when they were elected, or they had finished the obligation of their previously elected positions. If you can think of anyone else, I'm all ears.