“They’re all wary of doing something that looks like they’re giving someone a break,” said Rachel Barkow, a law professor at New York University, citing the “ Willie Horton effect.” Mr. Horton raped a woman and stabbed her boyfriend while released on a prison furlough program in Massachusetts; his case was featured in an ad attacking the 1988 Democratic president ial nominee, Michael S. Dukakis, who had been governor at the time of his release.

“That concern that anything that might be viewed as a benefit or an early release could come back to haunt you makes politicians very wary of doing these kinds of things,” Professor Barkow said.

Lionel and Keith Henderson were initially sent to the same prison compound but were housed in different buildings . Lionel was imprisoned in a more secure facility because of his longer sentence, which was the result of prior drug convictions. Their only contact for the next 13 years was through a prison email service.

In 2014, Keith’s sentence was reduced by more than four years after federal sentencing guidelines were lowered for many drug crimes, but he still had years to go.

Lionel walked free in 2017 , among hundreds of people who were granted clemency by Mr. Obama just days before President Trump was sworn in. Keith’s last petition for clemency had been filed toward the end of Mr. Obama’s time in office and was not reviewed.

Keith rejoiced at his brother’s release, but knew his loved ones, including his four children, were waiting for him to get out, too.