You can file this one along with my prediction that Clinton will not announce herself as a candidate for 2020.

This is entirely possible.  Hillary is 1st and foremost a political animal and may not want to risk the embarrassment, but I think, based on her current actions/rhetoric, there is a better than 50% chance you are wrong.

We have had a nice GDP sugar high from the tax cut.  I predict that 2019 and 2020 will both come in at less than 3% growth.  

Again, certainly possible, but you 1st have to assume that increased worker participation rate and increasing median income coupled with increased investment and accelerated growth in the majority of sectors will have a fleeting impact.  Seems there is a high potential for flaws in that assumption.

Deficits will rise due to the give away to billionaires (oops - I mean tax reform).

This premise is flawed from the start since it's based on a giveaway to billionaires.  The tax reform was more far reaching than that with impacts at nearly every socio-economic levels. I fully expect increased revenue with the growth we have seen this year reflected in April as personal taxes are paid.  What congress choses to do with that increased revenue is not a question I can answer yet.