The last Republican businessman to become president with no experience as an elected official was Herbert Hoover. He had been very successful in business and as an appointed administrator. How did that work out?

For one thing Hoover signed the Smoot/Hawley tariffs that helped create the great depression. He also started some of the policies that FDR expanded later like higher taxes and public works projects. Overall his presidency was not very successful.

So the fact that someone is a successful businessman doesn't necessarily mean they would be a good president. Just some food for thought.