Sen. Chris Van Hollen is drafting legislation to make the forcible removal of passengers from commercial airlines illegal.

The Maryland Democrat circulated a “Dear Colleague” letter Wednesday, seeking co-sponsors for what he is billing as the “Customers Not Cargo Act.”

“It is outrageous that airlines can bodily remove passengers after boarding rather than providing appropriate incentives to encourage volunteers. Airlines should resolve these common overbooking issues prior to boarding,” Van Hollen wrote to his fellow senators.

[Opinion: You May Rush to Judgment on United Incident — But Don’t Rush to Regulate]

The draft bill would direct the Department of Transportation to update current regulations on how passengers are compensated for being bumped from commercial flights in the event of overbooking or to make seats available for crew.

It’s an obvious, direct response to the forcible removal of a passenger Sunday by aviation security at Chicago’s O’Hare International Airport from a United Airlines flight.

“We were all shocked and outraged this week when United Airlines forcibly and brutally removed Dr. David Dao from Flight 3411,” Van Hollen wrote. “That is why I’m introducing the Customers Not Cargo Act to prohibit airlines from forcibly removing passengers after they have already boarded the plane due to oversales or airline staff seeking to fly as passengers.”

Van Hollen is not alone in seeking answers and changes. His announcement follows a Tuesday letter from 20 Senate Democrats to United CEO Oscar Munoz questioning the airline’s policies. That group included Minority Whip Richard J. Durbin and Minority Leader Charles E. Schumer.

“At a time when the airline industry is earning record profits, it is our hope that the industry can make great strides to improve customer service and implement best practices. Consumer trust and confidence are critical to ensure this industry continues to thrive, and we hope United Airlines will work diligently to immediately address this incident and make necessary improvements to ensure it does not occur again,” the senators wrote.

Van Hollen also signed that letter.

In a separate letter, also dated Tuesday, the bipartisan leaders of the Senate Commerce, Science and Transportation panel and its subcommittee with jurisdiction over aviation matters sent a series of questions to Munoz about United’s policies on involuntary rebooking.

One question asked how frequently law enforcement personnel are used to remove passengers from flights that they’ve already boarded.

“The last thing a paying airline passenger should expect is a physical altercation with law enforcement personnel after boarding, especially one that could likely have been avoided,” wrote GOP Sens. John Thune of South Dakota and Roy Blunt of Missouri, and Democratic Sens. Bill Nelson of Florida and Maria Cantwell of Washington.

Another question asked whether additional incentives could have been offered by United personnel to get people to agree to voluntary rebooking.

Munoz promised that an incident like the one aboard the United Express flight from Chicago to Louisville “will never happen again,” during an interview with ABC’s “Good Morning America” that aired Wednesday.

He said police will not be used to remove passengers in such circumstances in the future.

“It was a system failure,” Munoz said. “We have not provided our front-line supervisors and managers and individuals with the proper procedures that would allow them to use their common sense.”