Washington (CNN) Florida Democratic gubernatorial candidate Andrew Gillum said Thursday that President Donald Trump has provided "cover" to people who are racist and has contributed to the degradation in the nation's political discourse.

"I have not called the President a racist, but there are racists in his sympathizers who believe he may be, which is why they go to his aid, which is why he has provided them cover. I believe his cover has led to much of the degradation in our political discourse," Gillum told CNN's John Berman on "New Day" Thursday.

On Monday, Trump posted on Twitter that there is a choice in Florida "between a Harvard/Yale educated man" -- referring to the GOP candidate Rep. Ron DeSantis -- and a "thief," referring to Gillum, for governor. Critics decried Trump's attack as a racist dog-whistle.

DeSantis has seized on Gillum's 2016 decision to accept a ticket to the Broadway show "Hamilton" from a group that included an undercover FBI agent, according to text and email records released under subpoena last week, as evidence that an ongoing federal corruption probe in Tallahassee is closer to the mayor than had been previously reported.

The corruption probe centered on whether developers successfully influenced city projects. No one has been charged with any wrongdoing.

Read More