Sen. Tom Cotton, R-Ark., peppered President Biden’s Supreme Court nominee Ketanji Brown Jackson with questions Tuesday over her reduction of the prison sentence of a convicted drug dealer using guidelines set forth in a criminal justice reform law signed by former President Donald Trump.

During the first full day of questioning at Jackson’s confirmation hearings before the Senate Judiciary Committee, Cotton, a conservative hard-liner, focused on the case of Keith Young, a Washington, D.C., man convicted in 2018 of drug trafficking and weapons charges. Police found Young with 2 kilograms of fentanyl-laced heroin, a gun and 170 rounds of ammunition. Due to a sentencing rule based on Young’s prior conviction on a minor drug charge, Jackson, then a federal district judge, handed down a 20-year prison sentence.

But in December 2018, Trump signed into law the First Step Act, a sweeping criminal justice reform bill. It includes a provision stating that drug sentences would only face a mandatory increase if the prior conviction was for a felony.

“Congress changed the law, Congress decided the old penalty, the old crime was no longer eligible for the increased sentence,” Jackson said in response to Cotton’s questioning. “So what I determined under those circumstances was that I would re-sentence Mr. Young to the penalty that Congress had decided was appropriate.”

Cotton, however, argued that the law did not allow for judges to reduce sentences retroactively.

“Congress did change the law in the First Step Act, it was a big mistake. But Congress specifically did not make it retroactive,” said Cotton, who has been teasing a White House bid in 2024. “You chose to rewrite the law because you were sympathetic to a drug fentanyl kingpin.”

“Respectfully, senator, I disagree,” Jackson replied.