Morning Joe co-host Mika Brzezinski revealed Monday morning that she once confronted then-candidate Donald Trump off-camera about his “birther” campaign against Barack Obama—and that he told her privately: “I know it’s bad. But it works.”

The revelation came during a discussion of the role of race in the midterm elections on the MSNBC morning show. NBC News reporter Heidi Przybyla noted that attempts to besmirch black politicians seem to have backfired, at least in the case of Republican gubernatorial candidate Ron DeSantis, who told Florida voters not to “monkey this up” by voting for Democratic rival Andrew Gillum, who is black.

After that comment, a flood of racist robocalls came into the state, followed by President Trump calling Gillum a “thief.”

“All of these dog whistles,” said Przybyla. “And what did we see? We saw the polls tightening.”

Now, Gillum is leading in the polls.

Meanwhile, in Georgia, a robocall went out to voters this weekend with a voice impersonating Oprah Winfrey that calls gubernatorial candidate Stacey Abrams “a poor man’s Aunt Jemima.”

In a series of campaign appearances, Trump has claimed Abrams wants to “get rid of the Second Amendment,” would turn Georgia into a “sanctuary city,” and that she is “not qualified to be the governor of Georgia, by any stretch of the imagination.” Abrams would be the first black woman governor in U.S. history.

“The final several weeks of this campaign has been about racism,” co-host Joe Scarborough said. “Donald Trump has made up a story about an invasion of brown people coming to the United States.”

He was referring to the “caravan” of about 5,000 migrants, including children and pregnant women who fled Honduras, which reached Mexico City early Monday. The group is still hundreds of miles away from the U.S. border, but President Trump has ordered U.S. troops to stop them from crossing, has given officials a green light to open fire on any who throw rocks at them, and has floated the idea of completely closing the southern boundary, if necessary. He has also threatened to cut aid to Honduras, El Salvador, and Guatemala.

The dog whistles about politicians of color and fear-mongering surrounding the caravan have done more harm than good in the last days of the midterms, Scarborough said.

“Trump has reminded [voters] of Charlottesville every day over the last couple of weeks,” said Scarborough. “What does that do? That inspires Democrats, independents, moderate Republicans, and suburban Republicans to vote Democratic.”

Brzezinski then revealed that during a private conversation with then-candidate Trump, she and Scarborough criticized his campaign against then-President Obama, who he claimed was born in Kenya instead of the United States. Many decried the tactic as a racist attempt to bring down Obama, who was born in Hawaii.

“We confronted him about the birtherism,” Brzezinski said. “We said, ‘It’s bad, it’s wrong,’ and he said in a low voice: ‘I know it’s bad. But it works.’”

“Racism, in his mind, works. That’s what he told us,” she added.