A bill that would have kept driver’s hands off their phones failed to make it out of the state Legislature before the end of formal sessions last Tuesday night, disappointing supporters and even some critics.

Massachusetts has a ban on texting while driving, but not on making phone calls. Supporters of a further ban on hand-held devices say this opens a loophole for texting motorists who can simply pretend to be punching numbers into their phone. The unpassed legislation would have stopped drivers from making calls unless they use hands-free technology like Bluetooth.

The bill seemed to enjoy popular support from the public and legislature alike, but ran aground over a debate about racial profiling, even as voices on both sides of that debate advocated for the bill’s passage. Some bill supporters say a deadlock between law enforcement and legislators is what doomed it.

“One or two representatives really made it their mission to include data collection and focus on concerns on racial profiling. And they wound it up so tightly into any hopes of passing a hands-free bill. They just couldn’t get their ducks in a row and compromise with police, with law enforcement,” said bill advocate Emily Stein of the Safe Roads Alliance.

The representatives Stein is referring to are Rep. Byron Rushing and Rep. Jeffrey Sanchez, chair of the House Ways and Means Committee where the bill ultimately foundered. Sanchez refused repeated requests for comment for this story.

For his part, Rushing wants none of the blame for the bill’s failure.

“This is an issue because there’s a significant group of people, influential people, who don’t want this,” he said referring to law enforcement. “And I’m annoyed that I’m getting blamed for it.”

Rushing, the Democratic House Majority Whip, said in several media appearances preceding the end of sessions said he was worried that the new law would become a convenient excuse for law enforcement to pull minorities over at a disproportionate rate, and that he could not support a bill without provisions meant to deter racial profiling.

When the Senate passed its version of the bill a year ago, it included provisions that address racial profiling, which would have required law enforcement officers to collect demographic data on any person they pull over.

The bill attracted opposition from law enforcement, who said the data collection requirement was unfeasible.

“Many questions remain such as formulating a so-called “baseline” to determine the demographics of driving populations, the manner in which the data will be collected, and the increased workload to the municipalities and police departments that must manage and analyze this data,” wrote Dudley Police Chief and Massachusetts Chiefs of Police Association President Steve Wojnar in a July 25 letter to Rushing.

“At the end of the day, I would say the leadership chose not to put it before the membership to advance it at this particular time,” said Ways and Means Ranking Minority Rep. Todd Smola. “That’s why it never got pulled out of Ways and Means and never came to the floor.”

If and why Chairman Sanchez decided not to move forward with the bill remains a mystery. A public records search reveals that companies spent hundreds of thousands of dollars lobbying for and against the legislation. Some of the higher-profile entities opposing the legislation included insurance companies like Liberty Mutual and the cell carrier Verizon. Still, it’s not clear what if any effect the lobbying had on the passage of the bill.

The answer to why the bill failed is something that will likely remain behind closed doors. None of the individuals interviewed for this story said they opposed the bill, even those that had stipulations like Rep. Rushing and Chief Wojnar.

“This particular bill is something that is of great interest, I think, to many members,” said Todd Smolis. “I think it’s long overdue.”

Advocates say the need for a ban is pressing.

“Those of us who work in the traffic safety community are alarmed by the fact that in the past three or four years, we’ve seen the most dramatic spike in traffic safety deaths across this country that we’ve seen in 50 years,” bill supporter Mary McGuire of AAA Northeast said.

McGuire said devices like phones divert drivers' attention from where it should be.

“We know that distraction is a big part of that, and that distraction from the smartphone is a big piece of that. In 15 to 19 percent of all fatal crashes we know distraction is a factor,” McGuire said.

Driving analytics company Zendrive ranked Massachusetts last year as the state with the 10th most distracted driving.

But for some supporters, the repeated failure of Beacon Hill to pass the bill has led to a loss of faith in the legislative process. Emily Stein of the Safe Roads Alliance said her organization would begin a petition to put the ban on a ballot because legislators have taken too long. “I don’t know,” Stein said. “I thought we did everything right this session, and it still doesn’t get through.”