Nevada Democratic Reps. Shelly Berkley and Dina Titus were among those who had expressed support for Miller's effort — in part because it initially included provisions to protect construction workers — but ultimately voted against the amended bill.
Titus said in a recent interview that the legislation should have focused only on coal mining.
"If the bill was not as far-reaching, it would have had a better chance," she said.
Berkley did not respond to requests for comment.
Titus received $21,000 in campaign contributions from mining interests during the 2010 cycle, and Berkeley received $22,000.
Just before the House voted last December, the Chamber of Commerce designated the bill as a "key vote," a signal that it could be used to help determine which candidates to support or oppose in upcoming elections.
The bill failed to win the two-thirds majority necessary to pass in the House during the hectic lame-duck session.
The Obama administration's mine safety chief, Joseph Main, said that despite the legislative failure, his division launched its own surprise-inspection initiatives, issued unprecedented shutdown orders and obtained funds for increased personnel to help reduce the backlog at the Federal Mine Safety and Health Review Commission, which considers appeals from his division.
The agency issued 20 withdrawal orders at another Massey mine last month after a surprise inspection revealed conditions that "place miners at serious risk to the threat of fire, explosion and black lung."
While Main said he believed mines were safer today than they were a year ago, he acknowledged that his effort had had only a limited effect. In part that's because of the backlog: Increased enforcement produced more citations, which produced more appeals, contributing to longer delays.
Among family members of the dead miners, the inaction in Washington has brought a mixture of disappointment and despondency.
Last year's 48 mining deaths represented the highest fatality rate in coal mining since 1992.
"How many lives is it going to take before Congress realizes that these miners need more protection than what they've got?" asked Clay Mullins, a miner whose brother died inside the Upper Big Branch mine.
Hamburger reported from Washington and Smith from Los Angeles.