Ahead of a South Carolina Democratic primary election that will hinge on the black vote, Sen. Bernie Sanders (I-Vt.) criticized former Secretary of State Hillary Clinton on Wednesday for her role in welfare reform during the 1990s.

"I spoke out against so-called welfare reform because I thought it was scapegoating people who were helpless, people who were very, very vulnerable," Sanders said Wednesday. "Secretary Clinton at that time had a very different position on welfare reform. [She] strongly supported it and worked hard to round up votes for its passage."

In response to Sanders' comments, Maya Harris, senior policy adviser for the Clinton campaign, said in a statement that Clinton is "has long said she would work to address" the welfare law's shortcomings, "including the 5-year lifetime limit." Harris also noted that other reforms signed into law by Clinton's husband, then-President Bill Clinton -- such as an expansion of the earned income tax credit -- have helped the black community.

“When it comes to lifting more African-Americans out of poverty," Harris said, “it has been Hillary Clinton, not Bernie Sanders, who has put forward bold plans to create good-paying jobs, dismantle the school-to-prison pipeline, and remove barriers to sustainable home ownership.”

Welfare reform, officially known as the Personal Responsibility and Work Opportunity Reconciliation Act of 1996, turned means-based cash aid for poor families from an entitlement into a limited block grant with strict work requirements. President Clinton called the law the end of "welfare as we know it," touting it as evidence of Democrats’ willingness to reduce government dependency and work with Republicans.

Many Democrats considered welfare reform a betrayal, however, worrying that it would worsen living standards for struggling single women and their children in particular. Peter Edelman, now a backer of Hillary Clinton, resigned from his post as assistant secretary of planning and education in Bill Clinton's administration to protest the law’s passage.

The law passed the House of Representatives with just 30 Democratic votes. Sanders, at the time an independent congressman from Vermont, voted against it, as did Rep. James Clyburn (D-S.C.), currently a Hillary Clinton supporter and the most prominent Democrat in South Carolina.

As New York Times reporter Jason DeParle wrote in American Dream, his book about the 1996 welfare reform law, "Opponents [of the bill] had looked to Hillary Clinton to save the day, but the signals weren't reassuring." The president had already vetoed two prior welfare bills, and Clinton, who at the time held no formal office beyond that of first lady, believed that a third veto would be too politically costly.

"I agreed that [Bill Clinton] should sign it and worked hard to round up votes for its passage -- though he and the legislation were roundly criticized by some liberals, advocacy groups for immigrants and most people who worked with the welfare system," Clinton wrote in her 2004 memoir.

Today, there is an emerging consensus among liberal policy analysts and antipoverty advocates that their worst fears about welfare reform have been realized.

The number of Americans on welfare rolls declined precipitously, but not because of a corresponding decline in poverty. In 1996, 68 percent of families with children in poverty received welfare benefits, but in 2013, that figure had fallen to just 26 percent, according to the Center on Budget and Policy Priorities. 

The new welfare program has not kept pace with demand for a number of reasons. The federal block grant is not indexed to inflation, so it has declined 30 percent in value since 1996, according to CBPP. And since it's up to the states to determine eligibility for the limited pool of funding, enrollment levels vary widely from state to state.

Finally, critics charge that it is hard for people to find the jobs necessary to qualify for aid in the new system. It's just not easy to find a job in today’s economy as it was during the boom years of the late '90s.

A debate over welfare reform could have special resonance in South Carolina, where poverty is particularly acute. In that state, as in the rest of the country, poverty rates are disproportionately high in the African-American community.

Welfare-bashing has long been understood to be a racial dog whistle to conservative voters. At the time of welfare reform's passage, Bill Clinton told DeParle, he believed the law would help quiet the whistles.

"I really believed that if we passed welfare reform... we could diminish at least a lot of the overt racial stereotypes that I thought were paralyzing American politics," the former president said.

South Carolina state Rep. Terry Alexander (D), an African-American lawmaker backing Sanders in Saturday’s primary, believes that highlighting the differences between Sanders' and Clinton’s records on welfare reform is “going to have an impact” on whom African-Americans vote for. As it stands, polls show the state's black voters heavily favor Clinton. 

“It will send a message to have folks look at all of [Hillary Clinton’s] voting patterns on issues relevant to the African-American community,” Alexander said. “It was just eight years ago they came out hard against Barack Obama.”

Alexander believes welfare reform was “devastating to the African-American community in an attempt to pacify the right.”

“It took so many people off welfare and didn’t do anything with them,” he said.