■ Blacks have a significantly higher rate of church attendance than whites. So while some black intellectuals like Ta-Nehisi Coates, Michelle Alexander and Cornel West have backed Mr. Sanders, Mrs. Clinton is counting more on the black church.

An Upshot reader, Ed of Old Field, N.Y., wrote: “As white evangelicals are for Republicans, black evangelicals are an important constituency for Democrats, and Sanders in South Carolina will have as much of an uphill climb against their skepticism of him personally as Trump, for different reasons, had in Iowa. Not at all insurmountable, but a high hurdle.”

■ In the last South Carolina Democratic primary, black women made up for 61 percent of the black vote. In the 2012 presidential election, black women voted at the highest rate of any group across race, gender and ethnicity, and 96 percent of them voted for President Obama, according to exit polls. It is not an exaggeration to say that black women, in formation and flexing their political power, could have the final say over whether Mrs. Clinton beco

U.S. Democratic presidential candidate Hillary Clinton courted the critical black vote on Tuesday as she met with civil rights leaders in New York and promised in a speech to tackle "very real barriers" confronting African-Americans.

Clinton is seeking to maintain her lead among black voters over U.S. Senator Bernie Sanders of Vermont, her rival for the Democratic nomination for the Nov. 8 election to succeed Democrat Barack Obama, the first black U.S. president.

The Clinton campaign said last week: "It will be very difficult, if not impossible, for a Democrat to win the nomination without strong levels of support among African-American and Hispanic voters."

Clinton's status as the Democratic front-runner was jolted this month when the former secretary of state beat Sanders by less than a percentage point in Iowa's caucuses and lost to him by more than 20 points in the New Hampshire primary. More than 90 percent of people in those states are white.

He was referring to comments made by Sanders in Thursday night's debate, when the Vermont senator was asked whether race relations would be better with him in the White House than they are now.

“Absolutely," Sanders replied, "because what we will do is instead of give tax breaks to millionaires, we will create millions of jobs for low-income kids so they are not hanging out on street corners."