If he somehow manages to do it, hey, all props to him, but I really don't see him as a top 20 talent. I think his current ranking (between 30-45) is more accurate in terms of what he's able to bring on court but, yeah, he's being consistent and mostly beating the players he's expected to. I just can't see him as an established top 20 player as of now.
But to be a top20 a short time it doesnt mean anything, necesary.
I always put the same example: Granollers, is he better than Anderson?
Or Feliciano Lopez...I think those kind of players have some kind of luck in a few tournments at the year (Granollers in Valencia 2 years) (Feliciano Wimbledon) but so irregular the rest of the year.
Others than Anderson had to do much work to stay in the top30 and normally losing with players much better.
Another example: Kolsreiber, this year loses with Delpo, Tsonga,Isner, Berdych...just a few with player of lower rank, even he won a title but never has been a top20.