Sen. Kirsten Gillibrand (D-NY) on Wednesday night used one of former Vice President Joe Biden’s decades-old op-eds against him, reading aloud Biden’s lamentation that expanded tax credits for child care would subsidize “the deterioration of the family.”

She was referring to a 1981 op-ed in which Biden argued for helping low-income families and single parents with the cost of child care, but also for cutting off that support for higher income families. In his example, skewed a bit by four decades of inflation, Biden was concerned with expanding the child tax credit to “a couple making $30,000, $40,00, $50,000 or more a year.”

A tax credit for those families’ child care, Biden said, would let them “evade full responsibility for their children.”

The full op-ed, in which Biden describes day care centers and nursing homes “blossoming across the American landscape” as “monuments to our growing unwillingness to accept personal responsibility for those to whom we owe the most,” was helpfully posted on Twitter by the Gillibrand campaign’s communications director at the exact moment the senator brought it up in the debate.

.@JoeBiden op-ed in 1981: Expanding the childcare tax credit and allowing more women to work would subsidize "the deterioration of the family." Those are his words. He should explain to America: How does a mom working lead to the deterioration of the family? pic.twitter.com/RADnzTbofx — Meredith Kelly (@meredithk27) August 1, 2019

It was a seeming coup for the candidate’s opposition research department, though it’s not clear whether they dug it up or HuffPost did when the website reported on the op-ed last week.

Biden responded to Gillibrand Wednesday as he did in the op-ed, that he wasn’t opposed to the tax credit, but rather to its availability to higher-income families. HuffPost noted that, adjusted for inflation, Biden opposed expanding the tax credit to couples who would be making around $88,000 in today’s dollars.

Pointing to Gillibrand’s past praise for his positions on gender equality, the former vice president remarked: “I don’t know what happened except you’re now running for President.”