He could serve a third term and probably will attempt to do so, the two term limit could be wiped out with the stroke of a pen and Trump has a record for doing a lot of unprecedented things.
I pin my hopes on that failure continuing.
It's not even a new gambit. Putin did exactly this back in 2008 after doing two terms as president, swapping with his then-prime minister Medvedev for 4 years. Medvedev was also a nobody before becoming the prime minister, and there was absolutely no way he'd be elected if people didn't treat him as a figurehead for 4 more years of Putin's rule.
The bribing might be costly but people are more than willing to buy Trump's merch.