Democratic Presidential candidate Hillary Clinton speaks Feb. 26, 2016, in Orangeburg, South Carolina. Getty Images

On the eve of South Carolina’s Democratic presidential primary, the U.S. State Department released 1,500 pages of Democratic candidate Hillary Clinton’s emails from her tenure as secretary of state. Included in the 881 emails published Friday night are messages highlighting Clinton lobbying for a controversial Colombian trade deal she previously pledged to oppose.

During her 2008 presidential run, Clinton said she opposed the deal because “I am very concerned about the history of violence against trade unionists in Colombia.” She later declared, “I oppose the deal. I have spoken out against the deal, I will vote against the deal, and I will do everything I can to urge the Congress to reject the Colombia Free Trade Agreement.”

But newly released emails show that as secretary of state, Clinton was personally lobbying Democratic members of Congress to support the deal, even promising one senior lawmaker that the deal would extend labor protections to Colombian workers that would be as good or better than those enjoyed by many workers in the United States.

One of the 2011 emails from Clinton to U.S. Trade Representative Michael Froman and Clinton aide Robert Hormats has a subject line “Sandy Levin” — a reference to the Democratic congressman who serves on the House Ways and Means Committee, which oversees U.S. trade policy. In the email detailing her call with Levin, she said the Michigan lawmaker “appreciates the changes that have been made, the national security arguments and Santos's reforms” -- the latter presumably a reference to Colombian President Juan Manuel Santos. She concludes the message about the call with Levin by saying, “I told him that at the rate we were going, Columbian [sic] workers were going to end up w the same or better rights than workers in Wisconsin and Indiana and, maybe even, Michigan.”

Froman — a former Citigroup executive who as trade representative was lobbying for passage of the deal — responded by thanking Clinton for her "help and support.” Hormats, a former vice chairman of Goldman Sachs who subsequently was hired by Clinton at the State Department, later chimed in, telling her “terrific job” and “GREAT line on Columbian [sic] workers!!!!!”

Democratic presidential candidate Hillary Clinton greets supporters Feb. 24, 2016, in North Charleston, South Carolina, just days before the state's Democratic primary. Getty Images

Only a few months later, labor leaders contacted the Obama administration -- including the Clinton-led State Department -- raising concerns about what they said was abuse of union activists in Colombia, including against workers at a company linked to a major Clinton Foundation donor. The administration nonetheless moved forward with the trade agreement for Colombia.

Despite Clinton’s 2011 assurances to Levin that Colombian workers would get strong labor protections, union officials say violence against workers remains a significant problem in that South American country. A 2015 AFL-CIO report citing data from Colombia’s National Union School asserted that “in the four years since the United States and Colombia signed the Labor Action Plan — a precursor to the U.S.-Colombia Free Trade Agreement — to address entrenched labor rights violations, Colombian workers have suffered more than 1,933 threats and acts of violence, including 105 assassinations of union activists and 1,337 death threats.”

The majority of the emails published Friday night were classified as “confidential,” the lowest level, while almost two-dozen were classified as "secret” and another 22 were deemed “top secret,” which is the highest level of classification. The top secret emails were reportedly too dangerous to release to the public.

A State Department official said that none of the 88 classified emails released in Friday night’s batch had been deemed classified at the time they were sent. Clinton has been embroiled in a controversy surrounding the use of her private server during her time as secretary of state from 2009 to 2013. The email dumps, which are in response to a Freedom of Information Act lawsuit, have sparked a battle between the State Department and U.S. intelligence agencies, as well as Congress, over what information on Clinton’s server was classified and what was the routine business of American diplomacy, the New York Times previously reported.

Friday’s email disclosures also marked the second-to-last release from the State Department, and under the terms of a court order earlier this month, the department is required to publish the last of the 35,000 emails Monday, just one day before the Super Tuesday primaries and caucuses. In order to meet the deadline, federal officials have planned to work through the weekend.

"We’re still reviewing them – a lot of them, frankly,” State Department spokesman Mark Toner said, as the Hill reported. “Going to be working hard through the weekend.”