Democratic Tallahassee Mayor Andrew Gillum, who is running for governor, made the unusual move of proposing an tax increase while on the campaign trail Friday.

Gillum said if elected, he would increase Florida's corporate tax rate to 7.75 percent, up from the current 5.5 percent. That increase would generate $1 billion in increased annual revenue, he said, which he said he would use to boost education funding.

"Miami was shortlisted as we're competing in this contest (for Amazon's new headquarters)," Gillum said. "What is Amazon looking for? … Not only do we want a friendly environment for businesses to call home, but we also want to have an environment where they're guaranteed a workforce that is prepared."

That billion would allow the state to impose a minimum teacher salary of $50,000, allocate $100 million to construction of public schools and expand early childhood education programs and vocational training.

Florida's corporate tax was the brainchild of Democratic Governor Reubin Askew in the 1970s. The state has no income tax.

Eliminating corporate taxes was a big campaign promise of Gov. Rick Scott, which he has not completely fulfilled. He has, however, raised the threshold for taxable corporate income.