The big knock on it is that it takes years for a spaceship to achieve maximum velocity using Ion drive. Could they use a chemical drive to get it up to a decent velocity first, then switch over to the Ion drive to continue the acceleration?
“Attached hereto is a copy of Mr. Trump’s birth certificate, demonstrating that he is the son of Fred Trump, not an orangutan,”
That's exactly what they do. The initial stages include a booster to get it out of Earth orbit. But any more than that and you are trading a big reduction in payload delivered to the target for a shortening in time to get there.
Brilliant minds think alike, is what I always say. Soon you'll come up with the idea of using other planetary bodies to slingshot your way through the solar system, which is where you really get a boost in speed and for free too. Other than it takes a long time.