Retiring Arizona Republican Sen. Jeff Flake ripped President Donald Trump during a commencement speech to the Harvard Law Class of 2018.

"Your national leadership is -- well -- not good -- at all," Flake said, smiling to the students.

Flake said the "presidency has been debased" by Trump, whom he called someone with a "bottomless appetite for destruction and division."

The Snowflake, Ariz. native said Trump only has a "passing familiarity with how the Constitution works."

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He said Trump has left Congress helpless in combating what he called "moral vandalism" emanating from the White House on a daily basis.

Bret Baier asked Flake's caucus' leader, Sen. Mitch McConnell (R-Ky.) to react to the 55-year-old's remarks.

"Obviously I don't agree with that," McConnell said, adding that he however wished that Flake would reconsider his retirement.

McConnell said Trump's administration and the bicameral Republican majority in Congress has overseen a period of "extraordinary accomplishment."

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