Trump's racist attacks on Dem lawmakers are a test run in case he faces Kamala Harris in 2020: MSNBC contributor

Speaking with host Alex Witt on Sunday afternoon, an MSNBC contributor speculated that Donald Trump's racist attack on four female Democrats -- none of whom are white -- was a test run to see how far he can go attacking Sen. Kamala Harris (D-CA) should she be his opponent in the 2020 general election.

According to Democratic strategist Don Calloway, Trump may not have a grand strategy, but he's in "campaign mode" which brings out his barely concealed inner-racist.

"I'm not one to ascribe a strategy to the president when it's clear he's not a deep thinker, but he is, however, in campaign mode," he explained. "I see this as a good campaign device for him to gin up his base, fueled by the xenophobia and race-based hatred."

He then added, "I see this as an early proxy for what he will probably intend to do in terms of otherizing and isolating Kamala Harris; this is just the shoot-around or the warm-up for that, if you will."

"We've got to reach a point where thinking adults realize that, just because you're not wearing a white hood and have a swastika tattoo on your forehead, you can still be a racist," he lectured. "There's no question remaining in the minds of reasonable people that this president is a racist, and it didn't start with this tenure as president."

Watch below: