What I don't understand (I really do) is why would Trump want to run again if he thinks there are foreces out there stealing his victories.

Well first off, the notion that his victory was stollen allows him to make money off of his cult followers. Moreover, by the time of his 2024 run, GOP state legislators will simply be in a position to overturn any outcome not favorable to the Donald. So by hook or crook the GOP fix will be guaranteed by the next general election.

Remember, as Stalin said, what is meaningful is who counts the votes, not who voted for whom.