About half of registered voters believe President Donald Trump is racist, according to a new national poll released today, which showed voters are sharply divided along partisan lines on the question.

The survey was conducted by Quinnipiac University from July 25-28, several days after Trump said that a group of four congresswomen of color should “go back” to the countries they came from, even though all four are American citizens and three were born in the United States.

The survey period also included the day that the president launched a new attack on Rep. Elijah E. Cummings, a leading black congressman, calling him “a brutal bully” whose Baltimore-area district he characterized as a “disgusting, rat and rodent infested mess.”

The poll results come as Democrats seeking the party’s nomination for president prepare for a second round of debates, beginning Tuesday night in Detroit. Nearly all of the 2020 candidates have roundly condemned Trump’s remarks as racist and divisive.

The Quinnipiac poll found that 51% of voters think Trump is racist while 45% do not. When separated by party, 86% of Democratic voters classified Trump as racist while 91% of Republicans said he was not.

About 88% of those who said Trump was racist disapprove of the job he is doing as president, while 94% of those who said he was not racist approve of his performance.

It was one of several surveys in recent days that have offered a window into how Americans are processing Trump’s comments and assessing his core beliefs. National polls conducted by USA Today/Ipsos, The Economist/YouGov and Fox News in July have shown that between half and two-thirds of Americans believe that telling someone to “go back” is a racist statement and that Trump’s tweets “cross the line.”

On Monday, Trump again attacked a prominent black person — this time the Rev. Al Sharpton, a civil rights leader. Trump denounced Sharpton on Twitter as “a con man” who “Hates Whites & Cops” and again assailed Cummings.

He also linked the clash with Cummings to his demand that the four Democratic congresswomen of color — Alexandria Ocasio-Cortez of New York, Ilhan Omar of Minnesota, Rashida Tlaib of Michigan and Ayanna S. Pressley of Massachusetts — leave the country.

Days after Trump’s first tweets about the congresswomen, the House passed a resolution, largely along party lines, condemning his remarks. Trump has denied that his words were racist and called the House resolution a “con game.”

“Those Tweets were NOT Racist,” Trump wrote on the day the House voted to condemn them. “I don’t have a Racist bone in my body!”

The poll released today found that 41% of survey respondents believe his immigration policies are motivated by “racist beliefs,” compared with 49% who ascribed them to “a sincere interest in controlling our borders.”

The poll surveyed 1,306 voters nationwide and had a margin of sampling error of plus or minus 3 percentage points.