The moves stand in sharp contrast to Biden's career in the Senate, where he helped create a regime for the mass incarceration of people convicted under drug laws. 

"Sending people to prison for possessing marijuana has upended too many lives and incarcerated people for conduct that many states no longer prohibit," said Biden in a statement. 

His pardons will apply to nearly everyone convicted of simple possession of marijuana under federal law, but not to those convicted of selling or distributing it. It has no effect on the far greater population of people with state convictions.

While no firm tally has been released, officials say some 6,500 people were convicted of simple possession under federal law between 1992 and 2021 alone. The pardons will also clear thousands more convicted under the laws of the District of Columbia.

The move won't free anyone from federal prison: Officials say there's nobody behind federal bars today for possession alone. However, cleaner records will help eliminate barriers to finding jobs, leasing homes, receiving an education or receiving certain federal benefits. 

"I am urging all governors to do the same with regard to state offenses," said Biden. "Just as no one should be in a federal prison solely due to the possession of marijuana, no one should be in a local jail or state prison for that reason, either."

Despite his administration's welcoming posture toward illegal immigrants, Biden is not pardoning non-citizens who were in the country illegally at the time they were arrested.

In addition to the pardons, Biden did something else that has more far-reaching potential to bring a dose of rationality to federal regulation of intoxicants: He ordered Attorney General Merrick Garland and Secretary of Health and Human Services Xavier Bacerra to "expeditiously" review how marijuana is scheduled under the Controlled Substances Act.