A plurality of both Democratic voters and Americans overall said they wouldn't vote for a 2020 candidate who worked with segregationist lawmakers.

This comes after former Vice President Joe Biden reminisced last month about civility in Washington, mentioning his work decades ago with two segregationist senators from the South.

Vice President Joe Biden Thirty-eight percent of likely Democratic primary voters and 28% of Americans overall said they wouldn't vote for a candidate who had worked with segregationists.

Visit Business Insider's homepage for more stories.

A plurality of both Democratic voters and Americans overall said they wouldn't vote for a 2020 candidate who worked with segregationist lawmakers to reach compromises on legislation.

This comes after former Vice President Joe Biden reminisced last month about civility in Washington, mentioning his work decades ago with two segregationist senators from the South.

Recently uncovered letters divulge Biden's work regarding school busing in the 1970s. As a young senator, Biden introduced legislation banning busing mandated by federal courts. In June 1977, Biden wrote segregationist Democrat James O. Eastland to thank him for "efforts in support of my bill to limit court ordered busing."

Biden has recently defended his record on civil rights, saying at an event last week, "I fought my heart out to ensure that civil rights and voting rights, equal rights are enforced everywhere."

However, the work he did as a young man may impact his candidacy, according to our survey results.

We asked respondents to a SurveyMonkey Audience poll "What best describes your view of candidates who in the past collaborated with legislators who advocated for segregation?" Here's where the respondents broke down:

A plurality — 28% — of Americans said " I will not support them : Any candidate that worked with a segregationist politician to compromise on civil rights policies won't get my vote. "

" About 21% of respondents said " I really don't like it, but it's not a deal breaker: I don't like it, but politicians must sometimes work with people they deeply disagree with to get stuff done. "

" Another 12% of Americans said " I'm fairly fine with it : Politicians who work with people they strongly disagree with is an asset, even if they're segregationists. "

" And 9% said " I can empathize : Given the rapid pace of social change, not everyone can always keep up with such changes. I don't view this as a liability at all. "

" A further 13% said they "don't have a strong feeling either way and it wouldn't impact" their vote, while 17% said they did not know.

Zeroing in on the self-identified Democratic primary voters Biden will have to contend with in order to win the nomination, he's got even more of an uphill fight.

Substantially more Democratic primary voters — 38% — were opposed to the idea of collaborating with segregationists.

But about 27% of Democrats said it's not a deal breaker, but it's not exactly a plus.

Only 10% said the ability to compromise with segregationist senators is "an asset."

Read more: How the INSIDER 2020 Democratic primary tracker works

Biden's recent remarks provoked widespread criticism among Democrats, including fellow 2020 candidate Sen. Cory Booker, who asked the former vice president to apologize.

"You don't joke about calling black men 'boys.' Men like James O. Eastland used words like that, and the racist policies that accompanied them, to perpetuate white supremacy and strip black Americans of our very humanity," Booker said in a statement. "I'm disappointed that he hasn't issued an immediate apology for the pain his words are dredging up for many Americans. He should."

Asked if he would apologize, Biden was defiant.

"Cory should apologize," he said late last month. "He knows better. There's not a racist bone in my body. I've been involved in civil rights my whole career. Period, period, period."

Read more: Kamala Harris' appeal soars as Joe Biden's shrivels after their contentious Democratic debate

SurveyMonkey Audience polls from a national sample balanced by census data of age and gender. Respondents are incentivized to complete surveys through charitable contributions. Generally speaking, digital polling tends to skew toward people with access to the internet. SurveyMonkey Audience doesn't try to weight its sample based on race or income. The poll was conducted June 28-29, had a total of 1,172 respondents, 448 of whom were registered Democrats, and a margin of error of plus or minus 3.02 percentage points with a 95% confidence level. See this page for more details about methodology.