As President Donald Trump has traveled around the country rallying for candidates in the final days before the midterm elections, he’s argued that congressional Republicans would be better for the country on issues such as the economy, immigration and crime.

But he’s also put race at the center of his arguments, criticizing minority candidates with racially charged language, making baseless claims about threats posed by an immigrant caravan and promoting ads so controversial that broadcast networks declined to air them.

This week, CNN, NBC, Fox and Facebook all either declined to run or pulled an anti-immigration ad by the Trump campaign that compares a group of migrants fleeing Central America to an undocumented immigrant who was convicted of murder in 2014.

“CNN has made it abundantly clear in its editorial coverage that this ad is racist,” a spokesperson for the network tweeted. NBC then pulled the ad after running it, calling it “insensitive.” Facebook said the ad violated its advertising policy against “sensational content.”

When asked Monday about networks refusing to run the ad, Trump said he didn’t know about it. “We have a lot of ads,” he told reporters in the shadow of Air Force One’s wing. “And they certainly are effective based on the numbers that we’re seeing.”

“A lot of things are offensive,” he added in response to a follow-up question. “Your questions are offensive a lot of times.”

Even as networks refuse to run the ad, Trump still espouses the same message in it, often telling crowds at his rallies that the migrant caravan is full of dangerous people. On Oct. 22, Trump tweeted without evidence that “criminals and unknown Middle Easterners are mixed in” with the group.

“By the way, these aren’t babies,” Trump said in Pensacola, Florida on Nov. 3. “They broke through viciously.”

“When you look at that caravan coming up, that’s not what we want,” he said at the same rally. “That’s not for us, folks.”

Outside of border security and immigration, Trump has also made statements about black Democratic candidates that some have interpreted as racist.

“Dog whistle politics by its very nature exploits coded language that communicates a strong racial subtext but simultaneously allows the dog whistling politician to deny that he intends a racial message,” Ian Haney López, author of Dog Whistle Politics: How Coded Racial Appeals Have Reinvented Racism and Wrecked the Middle Class, tells TIME in an email.

Trump said at his rally in Pensacola over the weekend that Tallahassee Mayor Andrew Gillum, the Democrat running to become the first black governor of Florida, is “not equipped” for the job. “It’s not for him,” Trump said. Days earlier, Trump tweeted without evidence or context that Gillum is a “thief.”

“I have not called the President a racist,” Gillum told CNN after the tweet, “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.”

The president has also repeatedly referred to Stacey Abrams, a Yale Law School graduate who served as the minority leader in the Georgia House of Representatives and would be the first black woman to serve as governor if she wins, as “not qualified.”

“Regardless of whether you agree with their political positions, Abrams and Gillum represent candidates who have extensive experience in public service, impressive educational backgrounds, and can point to track records of accomplishment under their leadership,” Celeste Watkins-Hayes, professor of sociology and African American studies at the Institute for Policy Research at Northwestern University and a friend of Abrams, tells TIME in an email. “When credentials held by women, people of color, or both are dismissed or diminished, it harkens back to centuries of gender and racial discrimination in which individuals of great talent and skill were told that they could not access our nation’s most important political, economic, and social opportunities.”

Trump’s comments come as openly racist groups have targeted both Abrams and Gillum with robocalls in their state.

For other Democratic candidates, Trump links them to his favorite bogeymen across the aisle: Senate Minority Leader Chuck Schumer, House Minority Leader Nancy Pelosi and California Rep. Maxine Waters.

Waters, who is black, doesn’t have a leadership position like Schumer or Pelosi, but is almost always mentioned in the same breath as them at Trump’s rallies. (She is currently the ranking member of the House Financial Services Committee and could become chairwoman after the election.) He has previously referred to her as a “low-IQ individual” and at events the weekend before the midterm election sarcastically called her “legendary” and “genius.”

Some Republicans worry that Trump’s focus on racial identity politics so close to the election is undercutting their message to swing voters on subjects like the economy and health care.

But Trump, who began his 2016 presidential campaign by arguing that Mexico was sending “rapists” to the United States, faced similar criticism then and went on to win, and it’s clear that he’s going to run the same playbook again.

Get our Politics Newsletter. The headlines out of Washington never seem to slow. Subscribe to The D.C. Brief to make sense of what matters most. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Tessa Berenson at tessa.berenson@time.com.