"The economy is what I do well," Trump said Monday as he unveiled his plan to overhaul the tax code.

So far, Trump's promises to grow the U.S. economy by 3% sound fairly conservative, at least compared to Republican rival Jeb Bush's.

Bush is shooting for 4% growth -- nearly double what it is now.

Experts say: Trump's goal is a lot more reasonable, but his plan to get there is dicey.

"Three percent is very realistic," says Allen Sinai, chief economist at Decision Economics. "Candidate Trump has picked an easy target. Very clever."

History is on Trump's side

History is on Trump's side. The U.S. economy has expanded at 3% a year, on average, since the end of the Great Depression.

Bush's goal may be achievable for a short period of time, but most economists don't think it's sustainable. In fact, some experts caution that even getting America back to 3% growth will be a miracle (last year GDP was 2.4%).

There are real doubts that either Republican's plan could hypercharge the economy enough.