Trump is destroying Jeb. Jeb is going to spend soo much money fighting back 15 months out from the primary and his major donors know it and are right now recalculating their ROI on Jeb and are coming up very short.
Yup and here's the thing....Trump isn't spending near the amount of money that Jeb must. Much of what we see is driven by Trump. His ideas, his strategy. Jeb on the other hand has to pay minions to come up with strategies, do polls, etc etc.
Jeb is going to spend significant amounts of money in any war with trump while trump is going to spend relatively much less.