Trump has placed himself solidly as a target of the legacy establishments of both parties while effectively taking over the GOP through an ideological purge which sacrificed the House while solidifying his Senate. He's gained a bit more leverage where it counts if he keeps Presidenting while if he steps down he's made enough enemies to ruin his and his family's legacies if he doesn't follow through on Great Again.
The projects Trump quit as a business man, he quit because the downside of continuing outweighed the upside. It was a matter of throwing in the towel or actually losing by continuing to burn capital and influence. Now that he's in politics the math is different. He has to preserve his influence and his power by getting re-elected or the Deep State et al which had been indifferent to him as a businessman will bury him and his family.
The projects Trump quit as a business man, he quit because the downside of continuing outweighed the upside. It was a matter of throwing in the towel or actually losing by continuing to burn capital and influence. Now that he's in politics the math is different. He has to preserve his influence and his power by getting re-elected or the Deep State et al which had been indifferent to him as a businessman will bury him and his family.